Mongo's inclusion as a Horseman was ridiculous, it made absolutely no sense then and it makes even less now looking back at it. I think the Horsemen angle was overcooked in the same way that the NWO angle was eventually, its like the addition of Crush to Demolition.
If youre gonna change the lineup THAT many times, or even at all, find a new name for the stable and push them based on their own merits.