I'm not sure why mediums, Allied or Axis, have the ability to crush in the first place, to be frank. Is it really necessary?
Probably a necessity, or it could be literally possible for blobs to block tanks when they're next to terrain features. Crushing happens when infantry fails to get out of a vehicle moving into them - if they didn't die from it, the vehicle would be blocked by them, so without crushing, infantry next to terrain they can't walk through would block tanks from going through them either. Unless of course they made vehicles phase through infantry that can't get out of the way (probably something they'd rather not do for obvious reasons).
Of course, the Cromwell can run infantry over as they try to get away from it like all the time as long as its microed, soooooooo...
It makes sense in terms of realism, but it doesn't have to be soooo deadly and soooo imbalanced.
But it should probably take health off and then only sometimes kill instantly.
Maybe possible, though I'm sure they'd have to program a new facet into the game for that which I'd then have to say I wouldn't count on it from there.
Were they to curb it, they'd probably just reduce the relevant stats of the vehicles that are especially good at it.