it comes down to how precise your stomping needs to be. If you don’t really need pixel perfect stomping, then placing some collision box would be the way to go.
So it comes to the idea of hit box and hurt box like in fighting games. your character will have hurt box all around and only have hit box around it’s feet, on the other hand, your enemy character will have hit box all around and only hurt box on its head area. so the only viable way for your character to stomp properly will be approaching from top of enemy, because otherwise your hurt box will over lap enemies’ hit box first.
But if you need pixel perfect stomping, you might need to develop some custom collision shape or fancy collision detection in order to avoid some traditional glitches that are present in almost all stomping games.
However, I don’t think that’s really necessary, since if you place your boxes properly, it wouldn’t really affect gameplay at all.