If God is a more complex hypothesis than evolution, then he has to shoulder an even greater burden in providing sufficient warrant for assent. But Aquinas already through of that.  He asserts God's absolute simplicity.

Summa I:3,7 Reply to Objection 2. With us composite things are better than simple things, because the perfections of created goodness cannot be found in one simple thing, but in many things. But the perfection of divine goodness is found in one simple thing

God performs intelligent design of seven million species, listens to a billion prayers every night and decides which ones to answer, but he is simple.