Remember jobs are optional and one can forgo the option of placing the title on him/herself. Think of them as titles that grant/prevent certain abilities/traits/stats. This would in no way deter the dps of an ARC unless they chose to be a Bard. Archers won't have to balance attacking with buffing, Bards will. You could still run as GLA/CONx2/ARCx5 if you wished.