[GameExtremist]

I recently won a successful war against Hinnom using Ulm. They too were using chariots with melquarts.

First up - dealing with the tramplers - High Def units like your principe are as good as you going to get in avoiding getting trampled. Def Save Vs Trample. Mass these guys. a 4:1 ratio to each of his chariots absolute minimum. Have them at your back line with "Hold and Attack" orders

Then get some of your F2 mages - as many as you can muster behind the wall of principe casting bonds of fire (Thaumaturgy 2) to slow down the chariot charge, hopefully they arrive in smaller blobs so that your principe can overwhelm them.

I'd try and avoid fighting his main army until you can muster enough principe and F2 mages to beat him, make smaller armies and hit behind his lines if you can, possibly forcing him to split his larger army up again.

I used the same strategy above with Ulm but swap Principe with Shield Maiden and swap F2 mage with E2 mage casting Earth Meld. Once the chariots were gone the Melquarts went down amid a sea of shield maidens.

Good luck!