I grenade/JAW/C4 people who are below me frequently in Crash Site. C4 deals more damage and has a bigger AoE than Air Stomp by the way.
Infact the optimal opportunity to use a JAW is when you have a height advantage.
Perhaps I should have clarified that when I mean below you, I mean directly below you.
If they're underneath you enough that you cannot see them, you cannot JAW them, it's a pretty simple concept.
You're right, C4 does do more damage than a single airstomp; but as I said, a coordinated airstomp would do more damage, and notably also requires no ammunition.
I am 100% certain that 4-6 players simultaneously airstomping a crash site would be undefendable and cause multiple raging threads on this forum..