I didn't think you could snipe tank drivers anymore.... I only played H2 with scorpians on once near the start of release, but they seemed heinously overpowered, I started getting bored after racking up 20 kills and I just started chasing people with it and running them over. Granted you can jack the tank now, but without sniping then your only option is the rocket, which means that if you steal the rocket and jump in a tank......
i could be wrong though, it's a while since I drove a tank.