It is not a bad idea at all. I've thought before rugby in eastern Europe could consider a competition similar to the Kontinental Hockey League (KHL).
But as Croket66 says, start small and build from there. Super Rugby started with just six teams in the 1980s.
Could a Moldovan team be included, as rugby seems popular there and the standard not bad either.
I agree with this approach, start small. The beginning of such league would be only between Romania, Georgia and Moldova with a big maybe for an Ukrainean side from Odessa.
About Moldova, there were initial talks about one franchise of them to play in Super Liga but they failed to meet the task books of the competition at almost all financial chapters; for a Romanian club it wouldn't be a big hassle to travel one time / year at Chisinau for a game but for them it would be a huge task to travel for most of their games in Romania and there's not only about travels here but also about accomodation, insurances etc.
So it was easier for them to create a small league of clubs from Moldova and Odessa (Ukraine) which is semi pro and prizes are very small.
Regarding Georgia, there's a big setback which is the lack of direct flights between Tbilisi and Bucharest so you'll have to travel for a full day. Simply put, the economic relations between these two countries don't justify such a flight..hopefully yet.
Than, there's a vast effort of FRR to make Super Liga work. Ideally would have 8 pro clubs but so far only 7 compete but there are hopes for next year to add an 8th club. Club rugby (as opposed to frachises) is traditional for Romanian rugby and at some point we had like 200 clubs competing in various leagues (before 1989 of course). So to make franchises would be a big call and should be a certainty that this would benefit to Romanian rugby in general. There are rivalries, history of these clubs and we should be careful what we do if we don't want to end up like in Wales, Scotland or even Italy (anyone remember Overmach Parma) if we will destroy the clubs to replace them with franchises..
Not saying they are not open to good ideas but will have to outweight the benefits of Super Liga which were clear and obvious in last years. SL has merits in stopping the decline and finally is a professional sports product that was sold to a commercial television (Dolce Sport, subsidiary of German TELEKOM etc.)
Than there are cultural issues (outside of rugby) like reluctance in engage in contracts with entities from ex. Soviet space...see the continuous issues with Russian visas at every sport, not only rugby.
So I am saying it's simple to make these lists of clubs, teams, franchises, provinces...