Worst case scenario, you are playing with folks who are strangers and don't accept homebrew cards, plan to play your factual WWII vehicles in a "Counts As" format. This is of course if you really wanted to field the stuff. I'd play my Sherman as a Pounder, (though I wouldn't use jump just for my own suspention of disbelief to hold up), I'd play my Armoured Car as a Heinrich, Etc.
That's Worst Case Scenario. Average scenario is you're playing regularly with friends or a gaming group of the same people and they let you homebrew cards.