on average, most of the best decks are over 50% Trainers
I'm also sure that there are some benefits that can come from improving the mana base
Thats fairly cheap for a complete Commander deck, but there are some easy budget cuts you can make while you assemble this deck piecemeal
We went through various versions, but here's what we handed off from vision design: Afraid (If an enchantment, Horror, or Nightmare you control entered the battlefield or attacked this turn, all opponents are afraid.) This version interacted not just with enchantments, but a few of the creatures we felt most embodied the genre, Horrors and Nightmares
It can win or act as removal too, whichever is needed most, right
Golgari-Grave Troll will Dredge 6 and be a really big body on the battlefield with Regenerate evasion