State your sources please and thank you. I'll be more than happy to give a +1.
I kind of like the idea, but am not sure that it can be implemented without being abused. I think it is far more likely that the delay bomb would be dropped on a runway spawn than a tank (I sure would).
Again, what would be the point of dropping them on a runway spawn, unless you could predict a plane spanwning there 2 seconds after the bomb struck? The OP is discussing bombs that are detonated by a time fuse of a couple of seconds following impact, not detonated by the proximity of an enemy vehicle/aircraft.
Go ahead and roll your set of buffs off of a field where I can come across at low altitude with one of these and I'll show you the point in a heartbeat.