Ok, what we have here? From one side, leave only one system for each faction. That's universal. But leaves no room for system overtaking. Is it good or bad? In my opinion, good, if there still could be a reason for faction wars. If people are ready to fight for anything else apart from systems... this could work well.
Second, limiting system number. For Border World pirates, however, controlling many systems is illogical. And house factions are 'limited' by the number of systems their house owns, number that exceeds even the largest pirate factions in Sirius. Therefore, if it's pure roleplaying, pirates will always have less systems than house factions, which seems totally unfair to some... and to certain extent, it's truly unfair. Pirate factions on our server were never hungry for system control, except for one - AW. And as we are not interested in them quitting to play on the server, we'll have to treat them equally and set rules that will both disregard conquering too many systems and don't make playing too dull.