MTG: EDH / Commander

So I'm brewing up a [Anje Falkenrath] Madness deck. And I noticed the dual synergies with Vampires and Zombies a la [Stensia Masquerade] and [Dying to Serve]. Thus since it's causual and not cedh I though why not make it semi-tribal?

But I quickly ran into the problem with trying to do two tribes at once. I either run one tribe with a tack on, or I water both down too much. As such I come to you seeking wisdom. Any tips for makin a dual tribal deck work? Or is it a case of kill your darlings? Bonus points for card suggestion! Budget is a concern, but one or two semi-expensicve cards could be included.