breh, having a tank or humvee 2000 years ago would be a pretty bad idea I think
first off, we'd all die within 2 days of some shyt like malaria/bubonic plague
secondly, the terrain would be a major factor. What part of the world you're in would be a MAJOR factor. You ain't using no tank in South America or Africa (depends on area) 2000 years ago. You wouldn't even get that bytch off of the beach. shyt you wouldn't even be able to use a tank in America before the 1700s.
third, them nikkas is savages out thurr

The moment they realize the source of your power is from your humvee/tank, you'd be killed in your sleep. Ain't no Geneva Convention. Ain't no rules of engagement.
Defeat in battle, yes. Conquer and fukk their bytches, no. Not without a full squad.