I was just thinking that with the 20% minimal damage, armour is actually quite flexible as a balancing tool.
the spacetank could realistically be given eg. 4000 armour with the 3.0 value of 18k HP; it would function as nearly 100k HP against opponents unable to penetrate, while eg. anti-armour ships and heavy guns would still kill them, in a few shots- effectively recreating the performance of the much loved spacetanks of old (well, maybe with the addition of radar dampening to within about 10cm)
I also think zenith mirrors could be given huge amounts of armour, as this way the inflation to their HP in order to survive multiple reflections would not have to be so large (also, these need love desperately)
also, fighters are incredibly good atm- high speed, damage and HP. I was thinking, do they really merit armour? it dosnt make so much sense thematically- fighters rely on speed, firepower and numbers- and it would make weak rapidfire attacks like the MRLS & tractor beam starships more effective against them without use of artifical damage multipliers. it could also be a way to make bulletproofs stand out- 150 armour makes a BIG difference VS a salvo of 40 shots of 200 damage
armour in general should be given out much more conservatively imo. the armour ship would probably be better as just a HP sink with no armour so somthing other than fighters & starships can wear them down, for example, while all the little swarmy types should really have no armour at all