I don't know about being the best MA bless nation but I will say that wardens are tough customers. Add in even a light EN bless and they can make for some strong, cheap raiding parties. Adding in something like a frost brand on a lord warden or mage support from a mother of avalon and you can do even more damage (I speak from the experience of having had them used against me
).
I view them somewhat like TNN's tuatha warriors in terms of small numbers being surprisingly strong - the difference being that rather than avoid damage though high defense they can take a lot of hits.
They're not high profile like Mictlan's sacreds but I think they're a solid unit. I don't think going for a major bless would be wise but I also don't think they need it in order to be effective.
Actually, I haven't heard much discussion about MA Man under CBM 1.92. They got some significant boosts - the one that really stood out to me as being powerful is hex.