If the concern is connected with the RVT owning two rentals in the Savant at the current time, IC events led to the passage of property of said rentals. In the past, the Bellegarde Consortium (Port unofficial faction - Rival to the RVT) had at least 2 establishments associated with them that were managed by different players, with some degree of connection with the Bellegarde.
In all these situations, the rentals were used not as a faction base, but to promote other kinds of RP/Activities connected to the PCs (lounge, restaurant, whiskey bar + attorney office). To me, the association of a rental with a specific faction is a non-issue as long as broad RP involving players outside said factions is promoted (e.g., room for events and so on). Players belonging to a faction are just in the same situation as others when renting a space. Even if a brand is added on it, they are creating a space to promote a different avenue of RP, not an extension of the faction base.
This said as mentioned before, one rental per player is definitely a good choice as you need time and effort to run a place properly.