Hmm..let's see...yes, I think this could have worked!
First, instead of using four diesel sub engines, use a central nuclear power generator. Then, add self-adapting, self-repairing treads for traversing any terrain easily and quickly, and make other vital parts self-repairing. This would be similar to the setup on a Mammoth tank. Finally, construct the entire tank out of a carbon nanotube alloy.