Brutes has the most BDers and strongest pets on average, but the highest-ups (max league pets, WoDF/SuAP-level sets) are in different factions. Mostly in Sway, then Thieves. Order comes in at third.
mariokart is in Thieves for example; I forgot where 2truelavender, ghostkerdome, egaeus and that clique of peeps are in, but I'm sure most of them are not in Brutes.