Are you referring to me ?? I am still theorizing about group comps but maybe the place to start with are a couple crusaders on the 4 player and 3 player leaderboard using this build.
In a 3 person group, the crusader acts as the DPS for the group and has the advantage of not needing globes for resources. The globe barb therefore is not essential anymore (though the ignore pain will be missed). The other rolls stay basically the same: the monk groups mobs for the bombardments and the witch doctor buffs damage. That comp is ranked in the top 400 at the moment having cleared a GR 84
In a 4 man group is trickier. The team that placed on the leaderboards replaced the barb with the sader but kept a wiz on the team. The synergy isn't quite there and its reflected in there placement (just barely in the top 1000 with a GR 89) I wonder if it might be more viable to go double crusader ...
To come back to the question about LoN and group play. It seem to be a good alternative especially in Hardcore mode where there are several team running 2 LoN bombardment crusaders with 2 supports, usually monk and barb. On Hardcore, they've reached 86 on NA and 89 on EU. The number one group on EU hardcore plays with a LoN bombardment crusader and maybe 3 support including a wiz. someone will have to confirm if thats accurate but they cleared a 93 !