I don't know if you're talking about trying to cue up two rooms to playback a recording in near-identical time.
But for real-time playback with my Hopper3-connected TV and my Joey-connected TV tuned to the same "live" channel, the Joey TV plays back audio less than a half-second later than the Hopper TV.
If one were to correct this with a single-sourced audio solution like I described in my previous post, there's not much in a football game that would appear out of sync other than a talking head (or singing head in a halftime show).