Okay, so, in the long history of Romulans in Star Trek, here is a list of anyone they have used as a proxy or a minion without having attempted to assume total control of them first: Duras maybe, though given the anti-Romulan sentiment in the Klingon Empire and the stuff they had on him regarding the Khitomer Massacre he was probably so far in their pockets he had to look up to see the loose change.
It's a short list with more qualifiers than entries. This is a species whose list of defining traits includes extreme xenophobia and isolationism, to the point they fought at least one war around Archer's time without having ever been seen directly by anyone on the opposing side, and ghosted out on the galactic community from after that war until TOS. If they want proxies, they build robotic telepresences to do it for them and hold a gun to the head of the operator just to be sure. They've only affiliated closely with a literal slave species that we know of. Their official government stance during the 22nd Century was "Manifest Destiny 2: Manifest Harder" and that dream has not yet completely died judging from the way they're eyeing the Klingons now. Depending on how much you care about the novels the only reason they went into isolation after losing the war rather than rebuilding and going again in another few years was the result of a fratricidal spree of assassinations that left them without military leadership who could have actually prosecuted such a war.
Okay, I see your point. The problem is, the Romulans are no doubt in the same position we are, in that when they try to expand they bump into the territory of other species.
This is basically the question Briefvoice is asking: What can they do in response to that? How can they be a growing polity that's expanding economically and technologically?
Basically, there are two possibilities. One is that the Romulans methodically exterminate every alien species they encounter, excepting only those too powerful to destroy, whom they isolate themselves from. The trouble with this is that word tends to spread, and pretty soon the Romulans wind up ringed with nations that are armed against them and have every reason to combine against them. If that were happening, you'd expect the Romulans to have gotten crushed already. Or at least to be engaged in constant, eternal border wars on all sides with literally everyone, which isn't what we see the Romulans doing in canon.
The other option is that the Romulans have at least
SOME concept of diplomacy and interaction with other species. In particular, they have a proven track record of playing other species off against each other, or playing off factions within a species against each other. You can't do that with a species that you aren't interacting with on some level. You wouldn't even have any experiential basis for how to do it, because if you don't interact with aliens
at all, you won't know enough xenopsych and xenosociology to know how to manipulate them.
So maybe the Ked Paddah aren't "servants" of the Romulans, don't have an ongoing dialogue with them, aren't somehow in the process of being politically integrated into the Romulan Star Empire... but are still being in some way propped up and encouraged by the Romulans. Maybe they're not even a species or a nation as such, they're a faction that the Romulans are arming to make trouble for other factions, planning to swoop in and subjugate a larger region once its inhabitants are softened up by internal fighting. Heck, that's pretty much what the Romulans
tried to do to the four races that later became the Federation, back in the 2100s. Would it be a surprise if they did the same thing somewhere else?
So I just finished
making some adjustments. Right now I have:
1. An Academy expansion next Snakepit
2. Apiata expected to join by end of 2312
3. Assume that next Academy Steering meeting in 2313 we adjust intake towards officers.
4. 0.75 Casualties expected in every standard crew category every year; 0.25 casualties in Explorer Corps every year (Obviously this is meant to average out over many years.)
I'm not including any other members or affiliates right now.
@SuperSonicSound see link above.
(2) is probably optimistic. The Apiata are arguably at war right now and we don't bring in members who are at war. And while the Apiata caste issues have been
partially resolved, I don't think they've been
entirely resolved. That's probably going to require another event chain, over and above us figuring out a way to stop the Apiata from poking the Cardies and the Sydraxians hard enough to draw us into a war. All of which is likely to take more than a year to resolve.
(4) strikes me as a bit optimistic as well, especially as the size of the Federation and the fleet increases, resulting in more ships rolling more events, and therefore encountering more ways to get redshirts killed. Looking at the Explorer Corps...
I mean,
Courageous took nine points of crew casualties back in '09 all by itself. At 0.75 total crew losses per year (average over time), that would be twelve years of crew losses for the Explorer Corps. And, yes, that's pretty much the ONLY event we've had that killed large numbers of Explorer Corps- but we HAVE taken casualties before, even if you exclude the pitched battles of the Biophage campaign. Plus, for most of the past eleven years, we've only had three or four explorers operating at a time. In the near future we'll be up to six or seven... and the probability of high-casualty events scales more or less linearly with the number of explorers.
I doubt that our casualty rate over the 2310s is going to average a mere 0.25 each of techs, officers, and enlisted per year.
Similar arguments apply to the regular fleet, although when a regular fleet ship takes casualties we
often wind up losing the ship, which at least means our loss of crew is canceled out by having one less ship to fill with the crew in the first place.