I am going to make a Michael Vick dog fighting pit mod!
No I'm not.
Michael Vick tied to a stake and how many dogs? Typical Skyrim dogs or you thinking of including a Chihuahua or Yorkie mod? In the latter case a few dozen would not be unreasonable, although you may want to include ramps and scaffolding so they can reach.
(Wife sees this response over my shoulder and asks what the heck I'm writing about. I explain. She suggests 50 very friendly Newfoundland Hounds, standing outside the pit at the edge, slowly filling it with slobber...)