I like to mortar from behind the wagon, when axis are still defending the tank.
What can be really great is if you have a lot of mortar shells, and the Allies just repaired the tank. Lay off the fire, cuz you’ll like TK the Axis teammates near the tank. Listen for the tank to get close, then aim like 85-88 degrees and bomb down on many allies. I damaged the tank twice and killed many many engineers, and none of the allies bothered to check behind the wagon for me. it was pretty funny.
I ran outta shells, so I threw all my grenades over the wagon, another 2 kills. I then hear the familiar tank repairing sound so I whip out my knife run towards and backstab the engineer. Of course I died after that.