Many, many, MANY liberated Borg Captains in game, myself included.
A bit of a roleplayer, my bio explains that I was being assimilated and rescued mid-process. So I was never fully Borg, but now I'm not fully human.
With the popularity of 7 of 9, there are a lot of numerically named liberated Borg piloting vessels. This just seems HIGHLY unlikely to me, as Star Fleet wouldn't or shouldn't stand for it.
If you were "Tony Jones" when you got assimiliated, now that you are no longer 3 of 3 and half, (half being a midget Borg. It happens.), you should go back to your birth name. Star Fleet wouldn't encourage you to use what is essentially a prisioner of war ID, as it sets you apart, or worse, acknowledges that you are STILL Borg.
And while yes, several "babies" raised as Borg could join starfleet, never having "normal" names - it seems also unlikely that they'd make it through Star Fleet Academy, have an urge to join Star Fleet, period, or could adjust that well to life outside of the collective.