i just got my copy of "rise of vigil". i have every set made so far and have combined them without problem. what do you think about combining "rise of vigil" with everything? i'm just worried about diluting out the energy shards...I don't have the rules available, but don't the later expansions encourage you to stick within those "arcs" or "groups"? For example, some of the promos are only supposed to be used with certain sets, and SoS works best with IH, but not necessarily with just CotG or RotF.
If dilution is a big concern, I'd say just take out a percentage of non-RoV cards, and THEN shuffle them in with the complete RoV set to maintain a better ratio.