Well I don't think I explained the Irregulars good enough.
Basically, the average Joe Pubber is not going to have any interest in your school. That's just how it works. It takes a certain attitude and dedication to the game to want to persue schooling. Irregulars has no impact on the schooling, but it's more like a trap of sorts - you find the people who are motivated (and maybe don't know anything about a school), you lure them in the fence, and slam the gate behind them

Okay, not
quite that diabolical, but people are going to learn more and stick with something the more vested an interest they have in it. Average Joe Pubber would quit this game randomly out of the blue and forget about it forever. A good player who is able to find good teamplay opportunities will stick with a game longer than just a good player who's stuck on trashy pubs. Toss in a community as well, you got them. Irregulars snags up everyone from untagged members of this forum to new players who are expressing interest.
You do have to put a bit of a filter on it via basic applications to stop it from getting uncontrollably huge (and acting more like one of those MMO guilds that just invites everyone, and nobody knows each other), but the idea is the same - a 'casual' clan. The end result is you end up with a pool of players who work together a lot, develop skills together, and thus you achieve your original goal - you have a prime stock of clan-ready recruits.
Not knocking the school idea, I like it, but school works a lot better with a classroom, you know? That's what the Irregulars are.
Short version: Mech School are just lessons - Irregulars is the MWLL Sibko. I wouldn't call them 'Irregulars' though because that's kind of TG's "thing". Sibko doesn't roll off the tongue really well and implies youth. So I'm stuck on that. Bedtime though.... maybe something will come to me.