I'll bite...which one has ENOUGH traction? What are you willing to sacrifice to get it? Traction is the goal of course, necessary for forward movement, but it needs to be tempered by the capabilities of the equipment and power available. axles, motor, trans.
Look at it in extreme examples, a jeep with a 4.0 at 4k lbs vs a jeep with the 4.0 at 10k lbs. which one has the traction it needs? likely both. which one is putting more stress on every component?
You need as much weight as you need, anything more is a hindrance.
A stock jeep is heavy enough. You want the heavy armor or the light armor?