Will the May/Pac undercard be just as epic? Potentional Matchups?

I have a feeling that the undercard for this fight is going to be stacked. The promoters know the level of exposure any fighting on the undercard is going to get. Those fighters that might be the next PPV superstar will be the priority. Despite the fact that the lion's share of money is going directly to Manny and Floyd, you have to believe there's a substantial allowance to get other big name stars... Vasyl Lomachenko vs possibly Walters or Rigo(or Rigo vs Santa Cruz), a HUGE fight in it's own right, and all fighters in questions aren't as "expensive" as someone like Khan...while all fighters have the potential to be huge future PPV revenue generators.... So a win win for the fans and the promoters' budgets. Crawford vs Danny Garcia... a more expensive fight for the promoters but also a good "bridge" fight between Showtime and HBO (especially since the May-Pac fight will be on Showtime most likely) Stevenson vs Kovalev... another bridge fight, but also another expensive one. However, the Stevenson/Kovalev and Crawford/Garcia might be "too" big to be put in an undercard... Thoughts, opinions on whether we'll see an ATG undercard and the potential matchups(that are realistic... i.e. What fights are "big" enough to be a draw while not being "so big" that they demand their own event)