While L5R players are typically more loyal to their chosen clan than say a Magic player to a specific color, there will be a certain amount of players who are looking to play one of the top tier decks, regardless of clan.  You also have to take into account that there are a quite a few players that were loyal to clans/factions in the L5R CCG that have yet to get their own stronghold in the LCG, so they tend to freelance. 
For example, I was a Shadowlands player in the CCG, but, there is no Shadowlands faction in the LCG.  So, I chose Unicorn as my unofficial clan (since they were the worst clan upon release) to play with until my faction comes back, or I can at least field a legitimate Shadowlands deck out of one of the other strongholds.  Now that Unicorn is getting better and more people are jumping on the purple bandwagon, I might try playing a clan that isn't considered to be as good right now.  I like the extra challenges that come along with playing the underdog.