"tanker" is the wrong word... it doesn't mean a tank crew, it means a road or rail vehicle, or a ship, carrying liquids, notably oil.

"Tank crew", someone will come up with the right word.

Also, "armoured" infantry conjures up someone clad in a tin suit. "Tank support squad" or some such might be better, but I'll leave that to military experts.

I can't imagine many of the poor buggers singing this when there wasn't an officer around.