#1 They can go all out with the craziness
This is what I feel is the best part of a potential feud between the two men. King Corbin's matches tend to feel overbooked, especially when he brings all his lackeys to the ring. Normally people would roll their eyes at these shenanigans, but with the Fiend, it could add to the match.
Say it's a No DQ match between Bray Wyatt and Corbin for the Universal Championship, Wyatt is winning the match (because obviously). Suddenly, The Revival, Bobby Roode and Dolph Ziggler (heck, throw in Shinsuke Nakamura and Cesaro, because why not) all storm the ring. This will allow both men to fight on a somewhat level playing field.
They can portray The Fiend as vulnerable, which will get more people interested in the match. It's hard to care when one guy is practically indestructible. But giving Corbin the numbers advantage means he might win. He won't, but he might.
Plus, think of all the chaos and destruction that could happen when The Fiend lays waste to Corbin and his buddies.
Wrestling is all about chaos and unpredictability. This feud will have plenty of both.