Limiting the number of allied players

Sorry for the confusing title, nothing else I could describe it with. Here goes anyways.

In my map, there are 3 clans, and you have to pick to join 1 of them. Howver, there can only be up to 3 players joined to each clan. So my question is, how on earth could I detect that a clan has 3 members, thus stopping others form joining? (I can do the stop joining part, I just have to kill off the clan's diplomat) I'm sure it has something to do with integer variables, like one for each clan... Oh wait a second... I think I've got it, (hehe, thinking can help sometimes)

3 integer variables, one for each clan.
everytime somebody joins one of the clans (this is done using a dialog box, so I can use the "Player clicks button" or whatever event corresponds to dialog buttons being clicked), then set the integer for that clan to +1, and run a check. If, ClanInt = 3, then Kill Diplomat.

Would this work? Sorry for asking a question and finding a possible answer, it happens alot with me. So now, I just need someone to say that this would most likely work. Thanks a ton!
~Darwulfv

Yea, that would definatly work.
Thats one of the points for numbers :D.