I don't think the Order is quite capable (not in my saga at least) to put together the ideal "Avengers", but it will be a team built on politics and concessions (with good roleplay ops ofc). The self-important primi will want to make it look like unified strength, but isn't really.
I think the suggestions so far has been great, and a couple I hadn't thought about. I'll need to shortly figure the Orders shortlist (either canon NPCs, or some I make) - as well as figure the political maneuvering at the Grand Tribunal (and outside).
The characters will have some control of who gets picked (but not complete, as they're still "junior" in the Order). There will definitely be a Quaesitor or two, and some hoplites (mainly got those covered).
I can add that the saga 135 sessions in, has had less than a single handful of fights (but they have been in a couple of major skirmishes with the faeries). None of the characters, while actually very capable, are optimized for combat. One is even a pacifist - but he can heal, motivate and defend + bestow Enigma's Gift, even though he's not a Criamon. He's actually a Merinita converted from Jerbiton, IKR - long and crazy arc, but interesting. He made the switch to Merinita under Prima Handri's guidance - so is basically considered a filius.
I can also mention that the Tytalus character (Mentem and Vim specialist) was apprenticed to Prima Buliste (as a tormenting master) and she'll surely both deride and bully him on this as much as she can. Harpax may try to use him against Buliste. He's also the required Vim and portals master, who's found the mystic path to Durenmar, and will have to guide people and open the closed regiones.
The Tremere character (also Mentem specialist) is filius to Janus, spymaster of Tremere, and reasonably in trust - but not really (there's always internal scheming) and very capable (unbeknownst he's dabbled in forbidden Diedne secrets, including bone-biting and spontaneous techniques - ofc these can't be used too overtly).
The fourth and last character is a capable Verditius, who's decent at Perdo, Terram and Vim. His items will solve several problems (burrowing, visibility, negative aura and aegis-dampening).
As a separate campaign track (think similar to Dies Irae), the characters are convinced House Criamon is a huge conspiracy and will definitely try to avoid having any of them involved (which can likely fail). They've encountered Brighde (unpleasantly so) before, and she might be an interesting "pick" with multiple implications.
Archmagus Urgen ex Bjornaer is also a not entirely unlikely candidate, and known entity for them. But uncertain if he'd appreciate being on such a team (but he likes a fight).
Epicurean is a likely direct fit (or at least prominent in the process).