Depends on the temperament of your Texas. I have a school of 13 tetras in with my 18month old big male Texas and he doesn't care much about them as they are larger than his big mouth. Silver dollars are even bigger and I think would work well, unless you have a really aggressive Texas.
Good Luck
in a school they stand a better chance,they are usually fast and tough.it will depend on your fishes personality.some fish will not bother non-cichlid types,others bother only fish they are under a certain size