The problem with putting it in the Mandalorian Wars period is that it is being written out in the comics right now. We have an on-going timeline defining the exact occurences of what happens. The story is being written right now, and Dark Horse is not going to talk to BioWare and tell them how their story is going to turn out.
The MMO would stomp all over parts of the comic story if you run around meeting these characters in the game, and discontinuities will spring up everywhere.
I would hate to see that happen, especialy since I am reading the series right now. I am also enjoying the Vector series and am looking forward to see how it turns out in the last four issues in Legacy.