I'm not planning on having a single role, but a single chassis. If my chosen mech has 3 variants I can mech-lab 1 into a scout optimise the other 2 for other roles. I'm always gaining XP in different variants of the same chassis towards the Elite tiers I can fill whatever role needs filling. If a substantial number of other players think the same, you could see a lot of scout Hunchbacks scout Centurions, not to mention scout Dragons.
If you are the Lone Wolf - then it's alright. But no one can be equally good in every role at once and basing on my experience of commanding in the game-which-can't-be-named-here, i prefer to have under my command the people who specialized in one role, but performing in that role as close to the ideal as it's possible. Your chassis, your equipment, your modules, and finally your combat experience - all of these should serve to the one single goal - to do the specific job you're assigned for.
That's how the units which are fighting in the tournaments and at the Global Map are working. And i can bet - in MWO we'll see the same approach for the Merc.Corps.
Edited by Scar, 22 April 2012 - 05:05 AM.