First, some of the rules of engagement:
Battle Rule #1: Maneuverability is hindered more the faster you go and the heavier your vehicle. Faster mechs need to moderate their speed to keep control enough to evade when necessary, reserving full speed for when they have to get somewhere in a hurry. Heavier mechs ought to take great care as the armor will hinder movement some and reduce how fast they can go.
Battle Rule #2: The more firepower packed into one beam blast, the more ammunition and energy you use. There will be times when supplies are not plentiful, meaning if you use too much ammunition or power, you may be out of the fight for a while.
Battle Rule #3: Injuries or serious damage to your mech do not go away overnight. It could take days or weeks before your personal mech may be ready for battle again, meaning it is likely you may have to use another mech until that one is fully repaired. If injured, you might not be able to partake in the next battle.
Battle Rule #4: Do not expect to replace lost equipment swiftly each time. Resupplying could take a while, meaning if you lose a weapon you may need in another battle and you do not resupply in time, the situation could wind up much more serious.
Battle Rule #5: Taking damage in space is more life-threatening than in the air, because if there is a hole while in space, oxygen is likely to leak out, leaving the pilot unable to breathe if they keep fighting for too long. It also slows you down, meaning if you are too close to the atmosphere, you will get dragged in, and without an Atmospheric Entry System (AES) installed at the time, it will basically be game over for you before you even come close to a crash landing.
Battle Rule #6: Shielding systems can deflect and absorb plasma attacks, but are no good against metallic rounds or non-plasma blades. Sonic or Ion Weaponry, when properly developed, could disrupt the shields and leave a target more vulnerable. This necessitates great care in not being hit so much if the armor is pretty weak.
Battle Rule #7: The faster a mech goes, the more fuel it uses. Be sure to reserve going at full speed for when it is absolutely necessary. Otherwise, you would be wasting power.
Battle Rule #8: Hitting an enemy mech at the same spot will wear down the armor there, making that spot more vulnerable. Thus, it is crucial to avoid being hit in the same area the whole time. Once the armor protecting the cockpit cannot take anymore, the next time that spot is hit, game over.
Battle Rule #9: More often than not, a mech's cameras are located at the head, meaning if the head is taken out, you most likely will be running blind.
Battle Rule #10: No matter whether your mech is lightweight or heavy, chances of survival are higher in on the battlefield when you are not fighting alone. While I have no qualms with one on one fighting, do not expect everything to go as planned, as an ambush could come from any direction during your mech dogfight. Support units should be careful to shoot when it is all clear, so to avoid friendly fire that could endanger pilots on their side.
Battle Rule #11: While radar is effective, it cannot detect every detail going on if the enemy is in a low altitude if land is present. Plus, there is the possibility of the enemy jamming the radar so to render your ship unable to know for sure what is going on. There may be times when recon missions and patrols will mean the difference between life and death.
Battle Rule #12: Communication is key. Use advanced computers and communications systems to your advantage so that your teammates are aware of what you observe. If the others do not know what is going on, they cannot help you if they need to.
As an example of a verdict, I will use Zechariah and Aaron for this purpose (Note that my verdicts shall be in the form of which scenarios each would win or lose):
Zechariah Malachi Versus Aaron Lextu 
First off, we need to review the background of each found in the profiles, as that will play a key role in how they act, as well as experience-
Now, Aaron Lextu was someone who grew up in a pretty rough neighborhood in the tundra region of Metargo, where he not only had to deal with the bitter cold much of the time, but also the violent troublemakers whom often bullied him. It got to the point where he used one of his own swords (which he has been training to use from a young age) from his house to cut off limbs from his attackers out of revenge. He was able to avoid jail by agreeing to go to military school not far from his hometown. (Not that he never minded, since he wanted to get away from there so not to put up with all the abuse by his "neighbors".) By then, he embraced his military heritage due to the respect it gave him, as well as how people feared him because of it.
Not long after graduating and joining the Metargo Royal Navy as a mech pilot, King Saul took note of his skills as a swordsman, a pilot, and a leader (before that, those leadership skills went unnoticed because of them being shrouded by his angry persona). Saul personally invited Aaron's promotion to Sargeant and leader of the Lion Team, the deadliest mech squadron at the Kingdom's disposal. Aaron's first actual military battle took place shortly after that in the Second Metargo-Mysticaran War, where he gained the nickname "Falcon of Fury" for his ruthlessness and how he personally took down more enemy Golems (the magical variant of a Mech) in two years than most pilots could hope to do in three.
As for Zechariah, while he has a military heritage, he never embraced it fully, as the stories about it turned him horrified towards what goes on in war. When you add that to the fact he is such a fervent and traditional Deiangelist who does not believe in killing, to begin with, you can understand why he would focus more on Solar Technology instead of fighting, although he has been seen practicing his marksmanship before being drafted (he would not shoot to kill, however, if it came down to shooting, back then). He also took part in a few sports during school, adding to his athleticism as well as giving him a tan and dirty-blonde hair that both came naturally. His first true military experience came from when he was drafted and had to train in how to fight as a soldier/sailor and as a mech pilot, which he learned quickly.
I give the edge in experience to Aaron.
With that out of the way, we shall review their fighting styles. Now, Zechariah does better with speed and maneuverability than he does with raw power, preferring to make calculated moves to disable instead of kill. To execute this, accuracy is more important than firepower due to the fact too much firepower can ruin the possibility of sparing an opponent. to do this, fighting with ranged weapons equipped enables a better view of where to direct a hit since in melee, not only would you have to be close up, but also keep an eye out for incoming attacks, making it harder to find an opening in the enemy's movements so to find the correct place to strike.
While Zechariah's melee makes him capable of fending off attacks with beam swords and metallic blades, he does not know as much about fighting that way as Aaron does. On the other hand, While Aaron can hold his own with ranged weapons, he does better with swords since that is what he trained with from childhood. And so, in ranged, I give the skill edge to Zechariah, while the skill edge in regards to melee goes to Aaron.
In speed and maneuverability, Zechariah would have the advantage over Aaron, which is balanced by Aaron's edge in durability and, strength, and firepower. The downside is, Aaron's beam cannon requires most of the energy to use at full magnitude, meaning he has to reserve it in case of extreme scenarios, thus he resorts to his only other weapons, beam swords and metallic swords, the vast majority of the time, which would leave Zechariah with some time to try to wear down the armor in Aaron's mech from a distance, hopefully forcing him to retreat.
Zechariah has more weapons than Aaron, but they are all lightweight, meaning his speed is not hindered all that much. This means, however, that he has to aim carefully and make many of his shots count if up against a ship, which in regards to fighting Aaron would not matter unless he has to do two things at once. While the smart thing to do would be for Aaron to have backup as he fights Zech so that victory would be more assured, and vice versa, Aaron is too prideful, Zechariah too concerned for others' well-being, to consider such a move in a face off against each other. Later on in the roleplay, Zechariah will have mastered Ion Weaponry and would not have to worry as much about killing his opponents.
At last, we come to the final verdict between them. If Aaron can get up close for long enough, he would have the clear advatange after a while, except Zechariah's mech is faster, meaning he can provide himself with some distance so to avoid winding up dead. Distance will be Aaron's greatest enemy, aside from his opponent's speed and maneuverability. One mistake on either person's part, however (like, say, Zechariah going too fast to maneuver properly or Aaron losing too much speed to keep up) and the battle may be over sooner than expected.
I declare a draw between them because of the fact they balance each other out so well. It is up to their individual reactions to determine who will win in an actual battle.
Okay, now that you know how this will generally work, I hope this helps with resolving disputes between you in the future as to who would win.
