No, Valens is going full Zenos combat data. He's clearly experimenting with the best way to get it to work to his advantage. And yes Zenos has to come after Gaius, because Zenos is the more powerful and brutal soldier Gaius isn't.
Plus having an oversoul Zenos fight as the final trial is a use of material for the trailer to make us think the MSQ is giving us a showdown with Zenos but rope-a-dope us into something we can't see coming in the MSQ.