As far as I can tell from the main podcast feed, Tom has had another group for at least as long as the main RPPR group has been playing, that's where Aaron originally came in. Insofar as they have been mentioned on the main podcast, some of the players were uncomfortable with being recorded, thus why their games are not recorded and why they generally (with David being one exception) do not guest start in RPPR doings. I would have to guess upon reviewing the episode in question that the matter was discussed and then dropped.