There's definitely something in your idea. But melee will always hit and do damage while a spell has a chance to fail. You could do 2 guaranteed hits per turn with melee but the spell may miscast and result in taking 2 actions for 1 hit.
The Wizard melee is for killing off the little minions. If they get surrounded.
I wanted the players to have options for different tactics. So a Wizard could move and hit a critter, freeing a space for their hound to charge the enemy Wizard. That sort of thing.