Probably up to the Jihad Era, pretty much all* Raven Clusters were composed thusly:
Front Line: 45 Mechs, 75 Elementals, 30 Fighters
Second Line: 25 Mechs 125 Elementals 50 Fighters
Solahma: 50 Vehicles 125 Elementals 50 Fighters
Zeta Galaxy Chasseurs: Literally whatever you want, as long as it's mostly Protos
*(with the exception of the Wing Clusters and 1st Raven Phalanx)
Of course, it's your game, and paying Clan means that you can bid down. You don't *have* to stick to the Triad structure if it seems like a hindrance to you. It's more of a fluff guideline.
Furthermore, at least from what I've read from sources in 3145, Ravens are back to fielding stuff in a kind of willy nilly fashion post-WoR given their less than orderly exit from the Homeworlds.