If you mean WB @ 1st and 2nd, some other class @ 3rd, 4th, then WB @ 5th, 6th, then yes, you'll be able to get a 3rd lvl stance at 6th lvl (WB 4).. then again, you're only a WB 4 instead of WB 6, and at 20th lvl, you'll miss out on Stance Mastery as well as a 7th readied maneuver and the 13th...