Nerf the engineer class as it is too Overpowered

Nah, I see tankers get big KDs and I do ok myself.

It was a revelation to learn the 'crawl' function of the tank allows it to go over mines safely, but even so there are ways to scan for mines and destroy them remotely even.

Tanks do need support to survive a while, though. Repairs and a gunner that spots mines, etc.

They aren't supposed to last the whole game racking up kill-streaks unless they are very skilled or the team supports them very well.