Mine Clearance: What's the best way?

[Panzer VI]

I always thought the engine did take at least take quality into a account and fatigue....don't know about numbers.

I do agree on fact that each game is different. Try clearing mines as the Soivets in Stalingrad '42 and you will have a tough time, which is when #2 of the OP is more viable where most of the soviet army is morale C or lower.