Well you think of this.. This is 4,000 years in the past when the sith and republic are strong. Why not use their real names, that way they go down in the history books easier.
You know what could happen, you think your in the last battle with Darth Sion, he is about to say something, but is cut in two before it all comes out. Out comes Revan, whos been pulling the strings all along. Hopefully the last battle isn't on a super weapon.