I agree with what you say here about people recruiting SL's members, I was apart of SL2 (God, I never shut up about this) and I remember when SLa was made.
I remember this as it was created by Rojo and fairplay (I think it was fairplay) without the knowledge of many players (Aristocracy included) and so some players thought (me included) "Why stay in a tribe were you are told nothing and have no room to grow (Me personally along with a few K61 area players)".
This is but one instance that a few of SL's players left (my area really), I am sure there are many different situations that go along the lines of not being told things. Not being told stuff (as far as I am aware, if I am wrong please tell me) is a reason SL and SL2 merged, because the leadership were getting sick of not been communicated with and so left to join other tribes (Loftypurvis, Sweetbabydove, myself and a few other barons joined T:V eventually).
I also have to agree that during my time, the players either abandoned SL or left as they were recruited by other tribes, and it was infuriating, I remember personally mailing roughly 20 players in one week who left to find they had been recruited by other tribes. Also a few players left due to the T:V-SL war, it scared quite a few n00bish players.
I have to say, for SL to be where they are in the rankings and to have lasted so long with most of the lolliance tribes (and I admit some T:V) recruiting their players is quite amazing, but it would not be possible without constant recruiting (I do not agree with mass recruiting, but it is really the only way SL(2) could have stayed with people mass recruiting them).
SL might have been as strong as T:V in K51/k52/K61/k62 (Not T/W-TW) if only a lot of their players (maybe me included) would have remained loyal.