From what I read in the rules there is nothing to stop you moving through friendly or enemy tanks. Is this correct? What happens if at the end of your movement the tank would be overlapping a tank? What happens if you make one movement that would overlap, then rapid move to end up off the tank? Can you finish the first part of the move?
When the tank is destroyed it clearly marked as impassable terrain so you can't move through it then. What about a tank that is currently immobilised because of a critical hit?
I have no problem with the idea of moving through tanks as the movement is abstracted to steps and you can say the tanks coordinate to ensure movement is allowed. Parking on top of another tank till it moves would be very strange in a miniatures game though.
Hm... That is a rather interesting rules omission. Because this represents two dimensional combat (tanks aren't (generally) going to be rolling over each other), I would say that all tanks count as Impassible terrain. This keeps the rules simple and consistent, and still maintains verisimilitude.
If you want to simulate tanks coordinating their movements, you can allow tanks to move through Allied tanks, with the caveat that the tank(s) being moved through must move at least 1 template during their activation (marked with a Movement token to indicate this required movement).
Ah, I see they invoke the golden rule of 'leave it out of the rules so players can spend countless forum posts figuring how to play a common situation'. I don't expect a huge amount of detail in this game, it is meant to be fun and simple, and I'm willing to accept the abstraction level in movement but a sentence or two to say "yes, you can move through tanks but no, you can't end on them" in the main rule book is not bloat, it is just clarification for a common situation that has no rules guidance.