Since this actually did annoy me a little bit since I didn't know these games were intended to run at the same time...
You probably should not have gotten a green light from the mod, but rather from the individual(s?) who happened to be in both games. Because, I must imagine, it mattered a whole lot more to the overlap players than the mod. I would have dropped one if I knew they were both running. Instead, I've given a crappy performance in both. :p