texas cichlids stay fairly calm until they begin to sexually mature. When that happens they get preeeeeetty aggressive. They're generally only kept with other bigger aggressive cichlids. i feel like the silver dollars wouldn't stand a chance, and the rest of the tank mates would probably have a rough time too. Keep in mind that not all texas cichlids are like this, but all of the big ones i've met are.
i would say maybe switch to something like an oscar, which, in a tank that size, would have no problem getting along with those tank mates. If you don't like oscars cause they're too "common" there's still a lot of american cichlids around that size that would be less aggressive. But Oscar's are really cool...