Can a mount with the trampling charge feature use the bonus action attack against prone targets?

Question

I'm here with a rather nitpicky question. We all know that when you have a regular mount in 5th edition you can't make it attack while controlling it.

But what happens if the mount could attack as a bonus action, as per the second part of trampling charge (DM Basic Rules, p. 48)?

Trampling Charge

[...]If the target is prone, the horse can make another attack with its hooves against it as a bonus action.

So this is where I'm going: We have a shield bashing Paladin whom often knocks opponents prone in combat. If I then move towards said prone opponent could I have my warhorse attack using its bonus action?

The mounted combat rules don't really say: "You can't use bonus actions". All they mention about actions under your control is: "[...] and it has only 3 action options [...]". In every way, this doesn't seem to tell me that if my mount gets a possible bonus action (which might be an attack), it wouldn't be able to perform it under my control.

In the bonus action explanation there is this mention: anything that deprives you of your ability of taking actions, also prevents you from making bonus actions. But I guess this has nothing to do with specific actions and rather conditions like paralyzed.

So what do you think? Is it legit?

Answer 1

No

The Trampling Charge is an entire feature the second sentence hinges entirely on the first; you must make the hooves attack. However, if the target of the hooves attack were already prone then a) the saving throw to avoid being knocked prone is moot and b) you get the second attack automatically.

None of this can happen unless the horse is acting independently.; which is only possible if it is intelligent and you let it act independently when you mount it. If 2 counts as intelligent is a DM call.