As long as no one is getting eaten, let it play out. The bigger polys may show their dominance to the smaller ones. You may see a little nip at them and as long as that is as far as it goes just let them establish their pecking order.
The size difference is not that bad. If Lamar can swallow that lap down , he deserves the meal, lol. Just a joke. I think the size is fine. I would watch the ornate carefully, they can be the worst bullies.
I don't think either one of them could. The sens that the hybrid ate were half the size of these two. I can see that they really aren't that small now that they are in the tank with the bigger ones.