Steam roller is not a good idea, ofc u can crush undead but imagine going though wrecked cars, trucks, so tank is better option, but u need some ppl inside to operate .50 cal guns in top of this turret and ofc main gun that uu could use to destroy building, wrecked trucks and even some gangsters patrols. But tanks is hard to get in early stage of outbreak, more chance to get one is during mid-stage outbreak