sheesh... hanger defences get flack guns... are cheaper than sb upgrades... and so forth... There is NO reason to get strike craft upgrades on colonizeable gravity wells... or even better... 7 carriers... not only do they give you 14 squads of strike craft for less... you can move them around.
geezus... I mean you can use those 3 slots for alot better things than strke craft...
and if your upgrading a starbase to the max... then if you DONT have say... a kol with flackburst near by (recharged by the starbases docking booms and your culture... maybe toe occasional finest hour or flux field) then your nuts... and flackburst will beat 100 squads of anything.
with 1 kol and 2 donovs I can keep a starbase in even an uncolonizable grav well immune to bomber spam... they attack the starbase... flackburst and restore shield... the kol... flackburst, adaptive force shied and shield restore... and one of the donoves... flackburst and restore shield... he gets close... magnatize and use his own sc agaist him. I was playing a game where we both had starbases in the same gravity well... and we both had 50+ carriers in the gravity well.... I ended up just docking my SC so his capital ships stop getting exp from them... and just let my kol take care of it all.