The new system seems to have the romulans as a sort of 'neutral' faction that gets to choose at some point if to support fed or kdf and then gains access to enlist in kdf or fed fleets. This means romulans have no starbases of their own yet.
...but the romulans do have their homeworld and every existing fleet has an embassy there.
So why not use the concept of the embassy... just by flipping the situation around?
Since they have no starbases left (the nova blew 'm up) they build their headquarters planetside.
#1: Romulan fleet HQs are supersized embassy-type buildings. All cryptic needs to do is add one more transporter pad destination that lets players zone to the romulan fleet HQ (seperate little map.. waterfall with huge building in background, landed ships in pads, etc).
When the fleet is created and they get their planet-bound HQ it mirrors fleet embassies in romulus in that it only has 3 tiers to level up in. These tiers grant access to whatever tiered romulan content there is... but most importantly it also links their HQ with their allied kdf/fed faction fleets.
Here's how it works:
Romulan Fleet is created. Aligns with KDF or FED faction.
Once aligned, the fleet itself will, at tier 1 of their HQ, receive the ability to ally with an existing KDF or FED fleet. They gain access to minimal services at allied fleet starbase just like the allied fleet gains minimal access to romulan fleet hq.
At tier 2 the romulan fleet receives shuttle service to and from HQ and allied fleet and increased access to each other's stuff.
At tier 3 the allied fleet gains full access to each other's services and romulan fleet opens a 'floor' in their HQ for their allied fleet (KDF or FED themed floor) and same happens in the KDF/FED starbase: a romulan floor is opened.
Fleets can break and change alliances between each other. The romulan fleet retains the tier level when they 'transfer' their allied status to another KDF/FED fleet.
The benefit for romulan faction:
Full access to allied faction equipment. Decreased 'base grind' time.
The benefit to existing factions:
Full access to romulan faction equipment (except ships), no 'grind' time of their own to do so; can create a romulan-faction version of their fleet without having to re-grind a tier 5 starbase.