The other thing to consider with the Horses and Ravens is their washed out pilots ALSO end up piloting VTOLs- great place to stick the ones who have agoraphobia or whatever it is when they eyeball the black.
Like Scotty I would expect the Ravens especially and probably the Horses (especially with their tinkering with bloodlines for elstars? or tankwarriors? cannot recall) started Proto sibkos in the Early Republic era . . . but we really do not get a good look, afaik about the 'reconstruction' that happened after the Jihad. The Ravens already have Warship & ASF separate sibkos or at least bloodline/breedings IIRC. The greatest bulk of the sources on how everyone recovered from the Jihad are from MWDA's INN articles but that is written from a IS perspective and just the shallowest look at the Clans.
I would love to see the Cats return to being Proto users, but I am not sure they have the population on Marik or the 'enclaves' on other Protectorate worlds (aka garrison bases). The Protectorate's touman IMO would split between Clan born being mechwarriors, aeropilots, BA troopers, and DS crew while the freeborns raised for the touman mostly (but not all, we have examples) crew vehicles and cover PBI roles. I am not sure they can afford the diversification of their touman yet though that could change in a few years.
BECAUSE . . . if pushed early, the Cats could have sibkos pushing new warriors into the touman by '55 though '57 is more likely if I remember the dates. The real question is do they have any of the Nova Cat's legacies? I do not remember from MWDA's world building if Delta Galaxy brought a complete repository or just a selection based on the bloodnames that were a part of the galaxy when they joined Stone. IIRC it was hazy about how much they might have shared genetic material or even how the Bloodhouses were handled (GB, HH, and Wolf were in the same boat) but that is something BT has neglected for most of the existence of the Clans. Beyond that however, I do not recall any comments about copies of the legacies accompanying Rikkard even if his mission had Kev Rosse's blessing- just that Rosse was dead and no more Spirit Cat forces were expected to join them on their staging world.
So where does the legacies come from that the Protectorate used for their first generation of sibkos?