It's an optional roll
In "avaliable positions" (sorry if the spelling is not the same, my book is in spanish), where it instructs you to roll on table 3-2 to decide randomly your initial status, it specifically says "This table contains an option to calculate the initial status in case of dispute or doubt" (again, most likely not literal, translating). Rolling there for a sworn sword and having a 6 status sworn sword would be absurd, as would if you did so for a septon o a maester. And there doesn't seem to be any doubt or dispute among your players. So just let them have 3 status as they should.
That being said, you could still roll if you want some randomness, but I'd say roll 1d6 and have 1 being status 2 (fall from grace, bastard, not officially recognized, poor upbringing, whatever) and 6 being status 4 (landed kinght, special influence or titles within the house). Or simply have them decide which one is not recognized as a sworn sword even though they took the vow (status 2) and which one has been a confident and friend to the house lord for a decade (status 4). That way even though all your characters are sworn sword the status balance among them won't be perfect, which could lead to the backstabbing and plotting that make A song of Ice and Fire great.
Also, if one of the sworn swords actually has the official control of the province, his status should be 4 at least, 5 most likely (6 would be overdoing it, but since status has mechanical influence let your players have fun if they want).