How to prevent a unit from assaulting?

[Imp]

Assaulting can be an issue if all you have is a grenade, they could even suffer tank panic.
Just saying I like doing it the above way as you get 2 attempts, hopefully the AT weapon hit in which case it will be suppressed.
Must admit I love sneaking up on a tank from the rear, hard to pull off and only worth risking if you have support.