From what I have heard no,1 acc in you're attacks is plenty with rage,I personaly am gonna have 3 THBuffs in rage and 1 acc in attacks and im gonna be PvPing alot with him once I hit 40 
With 3 thbuffs in rage it gives a 78% acc buff which is alot more than 1 SO.
And even without the thbuffs it is a 50% buff so ether way you only need 1 acc in your attacks and thats only if you plan to pvp if you dont you wont need any acc in your attacks
It worth slotting 2 acc in powers still with rage ?