They will all get hit if they are in front of you, they will not proc affixes when fear locked anyway.. It just lets you be lazier. And until seasons end is a VERY good option I will agree. I'm not 100% certain the CHD from Laws of Valor applies to the group, the tooltip would lead one to believe it does NOT. I have been using Unstoppable for so long I am unsure though, derp!
I'm not sold, IF the grouping of mobs is good you will hit them all anyway, more pulling with season shield would help this, and condemn does good damage, and procs SA. I've not tried it though, without monk pull or condemn shield the final witness could SEEM better since there MAY be more chaos.
We were discussing this in clan the other day. I have a feeling Crus will not be a great replacement for monks until the season shield is available for pulling. That being said, the biggest thing is it has the potential to let DH hit 4.15 BP with 2H xbow! That's huge. Depending on the rift and the WD though you may be able to get away with it in some grifts.