Goddamned repair droids. Bastards can repair bunkers, even while they're inside of it. Worse, their repair ability stacks with other droids. Even with one droid, a bunker on Dathomir managed to withstand an attack from two gunships, an AT-TE, and even a goddamned
Jedi, and even a
goddamned bombing run, all at the same time. I eventually managed to destroy it by adding an orbital bombardment to the mix, hitting at the same moment an airstrike did. Hell, even if you catch the droids in space, their transports are mysteriously indestructable. And although Auto-battle can kill them, I once lost half my fleet against a force consisting of nothing but troop transports somehow.
Then I moved to Mygeeto, and after an hour or so of repeated attempts, during which I had to deal with respawning AATs(which cut down gunships pretty damn easily), and about 30 artillery tanks(which can cut down anything but gunships pretty damn easily). Eventually managed to pull it off by sneaking gunships around to hit scattered artillery, and then bombarded their base with my own guns after taking out their power generator with an orbital strike. Following this, I had to take out several more bunkers with repair droids. Artillery really helped here. Then the game decides to send me a gleaming "Fuck you" by simply deleting my army and rendering Mygeeto to neutral control. (A glitch, I later found out after taking Hypori with just Shak-ti, to be mostly caused by, infuriatingly enough, repair droids still being on the planet as they don't count towards victory conditions.)
Star Wars: Empire at War: Republic at War. Why can't my medical droids be that useful?