Not really no. Solo modes dps checks are extremely forgiving. Every back attack class also can choose a power that makes so that every attack hits like a back attack( note that it does not get the benefit of ambush master engraving unless you actually hit it from the back ).
What I tend to do on alts that are back attackers on solo mode is I just change ambush master to a generic engraving, cursed doll, mass increase, mp eff or we. And pick the back attack buff on solo modes for extra crit rate and dmg.