Hermeticism is likely to be more prevalent than the other traditions, in large part because Hermeticism is just more common. Path of the Wheel is terribly rare outside the Tir -- the other Tir, not Tir Tairngire, the close one -- and as such likely shouldn't be present unless you've got a really good reason for a foreign exchange student or something. They're awful urban and modern for Druids and Shamen, but depending on Mentor Spirit, I could see one or two of either fitting in...okay. But, yes. Like most modern and technologically advanced organization -- modern and technologically advanced, like the Tir Tairngire Peace Force many Ancients were trained in -- Hermetics should be far and away the most common.
It's important to keep in mind that there are many tiers to the Ancients. They aren't just a street gang full of Tarislar rabble. They are that, yes, but over the years they've also become much more. They're where exiles from Tir Tairngire often wind up (and in the last ten years or so, in-game, there have been a lot of Tir refugees for them to eagerly recruit from), and it's important to note that said Tir exiles are -- due to mandatory Peace Force recruitment, and Paladin options for the more wealthy -- often paramilitarily trained, and quite professional. What's more, the Ancients themselves run a pretty tight ship, at least in their upper echelons; they offer their services, legally and professionally, as a mercenary crew, remember? Licensed and everything, which gives them access (along with essentially running the smuggling lanes in and out of the Tir, and in fact all along the West Coast) to some top-notch hardware your average gang hasn't got.
Likewise, with magicians. They're more common in the Tir (due to being more strenuously tested, more socially accepted, and more encouraged to nurture their Talent) so they tend to be more common in the Ancients...and they tend to rise to positions of prominence. Of canon Ancients leaders, more of them are mages than not, remember. In Seattle alone, Wasp was a known combat mage, Green Lucifer (a secret mage) replaced him, Sting has long been the sole mundane, and now Belial (a mystic adept) has taken the reins. Even prior to Belial's recent introduction, mind you, that's 2/3 of them being Talented. Likewise, Firethorn, the overall leader of the Ancients (as per Vice) is described by Frosty of all people as having "enough Talent to make him really dangerous." When Frosty says someone's magically potent, it's best to listen.
Keep in mind, yes the Ancients are "just" a gang. But they're a gang with 15,000+ members worldwide, 350+ just in Seattle alone. Rated on scales of 1-5, they got a 5 in everything but magic and professionalism, where they received 4s. They are much closer to a professional paramilitary unit than to the Sons of Anarchy or something.