I've been playing this game for a few years now and the current state of the waves and API is getting out of hand. Every match I play feels similar in the fact that I either have a stalemate, lose, or survive by getting the botnet to kill the huge waves. This does seem to happen around the mark2 level for the AI.
It's not due to the mark level itself but for me it's the sheer number of units the AI sends at you. A huge fleet of 800 fighters is extremely deadly without the botnet golem. Missile frigates kill them at a good rate but not fast enough to deal with them in timely manner. And it's worse since the two waves usually come close together, thus having two huge waves on different sysems is a mess, even more so when the same hard counter ship is needed for both. The botnet golem does make quick work of nearly all waves but if you play without it I think you're insane to do so.
My current game has pretty much all options and plots on normal, easy golem, botnet, and spire, with 8/8 AIs. I can handle everything but the waves pre botnet at this time. I have my defenses spread out to prevent the AI from focusing waves so heavily and to defend against hives. It's working good until I got to around 225 AIP when the waves get around 800 to 1k mark 2 units.