[Deadnature]

I think that the point isn't to change elephants or other tramplers, like many people here said: some nations rely on them. Instead, I think the best idea is to give some units a boost against elephants.

My suggestion:

For every unit with a weapon over length 3 (all spears/pikes) that is successfully trampled, have that unit deal its base weapon damage to the trampler. After all, a wall of spears or pikes might not stop an elephant dead but certainly the elephant would impale itself in the process of trampling.

This is a soft nerf that makes sense. Elephants will still be powerful, but now there is a decent way to counter or at least slow them down. I mean, what sense does it make to see an elephant crush 10+/- pikemen without getting hurt at all? That's like trying to crush a beehive with your foot and not getting stung.

I think this idea with some modification would be acceptable to many people in regards to the elephant/tramplers question.