GW does have flanking and combat advantage. They try to do it when possible. The issue they're having is that they are evenly matched (5 characters vs. 5 opponents), so it's hard to "gang up" on them - especially when I am dropping characters faster than they drop enemies.Is your party working as a team properly? I dunno if GW has flanking and combat advantage, but is your party making use of synergetic strategy? Dod they have complimentary characters? Good teamwork can multiply the strength of a part in 4e.
As far as complimentary characters go, all character creation in GW is completely random, so there's really no character creation minigame.