Assault vehicles have 6 times more HP and but only 30% more damage against tanks/walls.
However, I think they should be considered in different roles. Some people use bazookas in wars because armies with them can clear a base quickly, but there's the oil cost to retrain.
I use 2-3 bazookas as a cleanup crew but when I used Assault vehicles (which I tried and discarded) it was as a tank replacement (front line troop), except they cost more than tanks, take up more space and don't have as much hp.
imo, neither of them are any good as a frontline troop or as the primary destroyer in an army in MP.
BUT, you should try them for yourself.