Seems to depend on class of other players in the party. If enough AoE nukers are around it's possible to pull a stupid number of mobs at once with Shield Oath, use Flash off the Blind cooldown and essentially spam TE while Blind is up. Some damage contribution is certainly better than the zero from Flash, and bringing down 10-15 mobs at once is still faster than doing them 3 at a time if the DPS classes are AoE-specced.