I'ma go play some more... I've never tried actually fighting those two tankers, I always just assumed I was supposed to retreat. Maybe if I save the MRL for when they arrive, I might actually have what it takes to kill them.
BTW, does anybody know what game I'm talking about?
Edit: I was unsuccessful. Damn warriors got up on the bunker and drove me back from the edge so I couldn't shoot down at the tankers. Then I basically just had to retreat... luckily I had taken out a lot of the blasters early on, so I didn't have to deal with them and the fireballs at the same time.