I have two 9500s and two 7500s. I can see and watch all my recordings on any receiver in the house. The 9500s have two tuners each. If those tuners are in use, the 7500s can still watch a recording but can’t tune to any other live channel until a tuner becomes free.
Don’t ask me they are hooked up because I don’t know. There is something called a hybrid duo hub that some cables go in out of as well as a channel stack splitter.