I have 3 O's from 7-8 inches and 2 Texas's about 2 inches, and I have to giggle every time I see my smallest TX come up from behind the O's and give them a nip on the fins when they go near his "home".
I fed my O's well b4 I dumped the TX's in the tank. My O's are able to eat feeders much bigger than the TX's are. The TX act as if they own the place, and act very dominent for a bunch of little guys. The O's never mess with them.
The have so much additude for their size, you should not have much to worry about. I did make lots of caves n stuff for them to hide in, they just dont feel the need to use them!
Good luck, but dont be surprised if you find your O hiding from your little TX!