So I haven't figured this out yet as there's lots to consider, but for these runs you obviously want to impair the CPU's as much as possible (in this case, by making them play as characters with not so great dice), the reverse is also true for the speedrunner, so the question is what are the optimal characters to choose.
There are a couple schools of thought, for the runner should you prioritise consistency with character dice like Shy Guy's or Daisy's, or do you go high risk/high reward and choose characters like DK or Bowser.
Like I said I haven't figured it out, but I think there should be discussion about it since people will likely have many different opinions (like with the runs currently where people are choosing different characters). Maybe it doesn't matter, in which case fuck it, but it makes sense you'd want the best circumstances for the run.