I recently shut down a couple of tanks to cut down on maintenance.
I put a small 3.5" Green Texas in a 150 with a 7" RD/Midas and 4 large Silver Dollars. It has been several months and all is well. The RD just chases the Texas sometimes, just across the tank. The Texas is pretty bold, he swims where he wants even hangs out with the RD/Midas sometimes. Don't know if it will last.