Sorry, the SuperBattle Droid is the one you're looking for if you want a wrist rocket launcher. The Assault droid is the primary rocket bot, not that I like it. I prefer driving tanks.
Destroyers are the ones that get destroyed and have that really dodgy name..whatever.
Anyway, I don't play online, so I can't comment on my strategy, works extremely well on bots though.
I am the definition of your defeat.