Thanks for the hint with fighters - in my tries i went straight MK3 cruisers and fighters and bomber starships now die quickly enough - but the ai has a real problem with the way shields are now
But - Number games (especially to balance speed and range) have no place in a tactical situation, the problem is increased because ships fire too early and waste an entire salvo (which is usually the ONLY salvo they get against starships) and do 0 damage.
I tested this now repeatedly and my 400 fighters do 0 damage (or maybe 5+ hits) to a starship that barely scratches their fire arcs, which is problematic to say the least. Because starships do not attack my fighters they literally try to out run me.
Instead of speed i think a dedicated anti-starship weapon needs to exist - one that is not a ship. That way the AI would get a good defense against starships as well (which right now, the AI has even more a problem with than the player)