While that may generally be true of hetero groups, the gay ones, judging by the several I've met over the last few visits to Bangkok tend to travel in small groups of friends. They are seldom alone, as you said, but the gay ones aren't in packaged tour groups either. For example, the four who checked into the same hotel last night looked rather gay to me, but I had no opportunity to test them out
However, travelling as a bunch of friends also means that offing boys from bars is out of the question (since they share rooms) unless they avail themselves of short-time rooms at Suriwong Hotel.