Grow a convict to their size and a dovii looks like a guppy…
That said, one is natively a Central American (dovii), and the other South American (pbass), so they are already “kings” of their respective regions (though of all the SA’s, festae is probably known for being most aggressive). A direct comparison isn’t really possible as both fill the same role where they come from. Dovii is famous for being the meanest cichlid, but pbass has a size advantage when it comes to what fits in its mouth.
Without a properly sized enclosure, any of these cichlids will unleash hell on their tankmates. You will only ever see one species dominating in the wild, but that changes based on where you are.