I do also acknowledge the downfalls of Proving Grounds since that's all I play (too impatient for matchmaking). These are some serious downsides, but there is always a positive. Every single AI in the game acts the same way. Every single T3 Machias is going to behave the same way as every other T3 Machias AI you can find. Because of this, you can simply outsmart the system. I play legendary proving grounds and here are some issues with the enemy gameplay I encounter:
-The Brutus and Vindicta destroyers are armed with Plasma Rams and disruptor missiles. When they boost their speed, you can tell that they're about to ram someone. If you're the target, start lowering your altitude, and the AI will NOT KNOW WHAT TO DO, it's actually quite funny.
-Any artillery cruiser (except Oberon artillery cruisers) will not fight back if you get their side. As a corvette, if you sneak around the back, you may encounter some enemy fire, but if the artillery cruisers aren't facing you, they likely won't fight back if you're fast enough.
-Jupiter Arms Corvettes are programmed to act aggressive, so if you charge one directly, they run don't know what to do and just sit there, either shooting you with the primary or secondary.
-If you face the situation where there are 1-2 tac cruisers on a dreadnought, the easiest thing to do is to just nuke and target the tac cruisers. If they're two oberon tac cruisers, it's better because the beam amplifier that they have also weakens their damage resistance, so if you time it right, you can do easily 50k damage with a nuke if you hit them directly. If it's the Akula Vektor tac cruiser, you may have some difficulties since this one's a meatball. If there are two tac cruisers, always hit the Oberon one first when it activates it's beam amplifier and hope you can do enough damage to it before the other tac cruiser catches on. Another tactic against the 2-tac-tactic is to trick the AI into only healing the other tac cruisers. Since they only have one beam at a time, do enough damage to them so they keep healing themselves and leaving the dreadnought under fire by the rest of your team. If both the tac cruisers are the Akula Vektor, just hope that a friendly Ram gets close enough to do it.
-RAMS. The rams always do damage to an enemy formation, even if it dies. When I play the ram, I always sneak around the back and kill artillery cruisers since it's a one-shot kill immediately. If the enemy is doing the 2-tac-tactic, I as the ram would charge into battle and ram the weaker one. Chances are it lives through it and its teammates kill me, but if I have enough time, the flak and ram can kill the tac cruiser. It's a one for one trade, which is never a good option when you're outnumbered 6-8, but if you can trade your life to weaken an already powerful formation like the 2-tac-tactic, do it.
-Lastly, remember that all the AI change the ships they use after they die. If you kill a tac cruiser from the 2-tac-tactic, chances are they wont respawn as another tac cruiser (but there's always the chance).
I hope this helped you in some way. I know this post was from July, but I still wanted to respond.
"Oh I got a hit marker, am I close?"
Hit me up or don't, not really my choice.