I don't ever recall entire map herding being something I ever had to put in effort to avoid. I'd run across it, sure. But never to the point I considered it a nuisance. I do however recall Tanks telling a team to sit and wait while they gathered being a very common thing, to the point I completely stopped actively recruiting Tanks. I wouldn't turn them away, but even when doing something like an STF(back when it was widely considered challenging), I didn't look for one. At this point in the game I don't look for specific ATs or powersets at all, I invite in order I see the messages. But if I'm filling a final spot on a team and I see a Tank and any other AT looking at the same time in a chat channel, I'll still send the invite to the other AT first. Without exception.