Eye of Terror, Page 43: (Paraphrase) Each Champion can take wargear at the points listed in the armory and the points listed for the Marks below.
It appears that each Champion has access to the armory separately. The Champions will operate in different units, so I don't see the Marks conflicting. I'd say go for it. I'm trying to look into it more closely, but you are permitted to give a Mark of Chaos to each of the Champions, and there appears to be no restriction on taking Marks of a different kind.