Yea, unfortunately 3 Tartans can take out an almost limitless amount of Fighters if they maximize firepower. You can definitely take out a hanger with your Y-Wings before they are all destroyed, but against a human player, you'd have to have more than 5 Squads of Y-Wings to take out a 2nd.

i just finished a galactic conquest as rebels on medium, on the 21 planet map. i'd say it took me a good 6 hours, thats only because the first four i would play out the very long land battles. after a while, i started auto resolving all the land battles and accept the losses, because i could replenish them really quickly anyway, not mentioning all the free units i was getting. besides, with some Y wings in orbit it seemed i lost less units (probably due to the bombardment). there was one or two defensive land battle that i played out which were really satisfying though

 

this was my first run at the game, i did the tutorials and didnt even touch campaign or skirmish (i was looking for a rebellion 2 game), and at the begining i thought it was hard, although once i read about hiting the hangars, space battles became extremely easy. if anything, hangars need more defense! i can't really think of any scenes in the movies where hangars got obliterated, not counting parts where an entire ship went down of course.

 

the turning point was when the empire cleared out a pirate system, i was then able to move onto the empire's newly acquired non reinforced planet. another factor was how fast it is to tech up and then get all those free hero units (ackbar, etc). by the time i conquered mon cal, the AI couldnt stop me.

 

the empire didnt build a death star, and at the end when i auto resolved the land battle on coruscant it showed the AI's loss as only being the emperor. I don't know if this means the AI only had the emperor guarissoned on corsucant or if the battle auto ends when the emperor is killed