#3 They already have some built-in feuds
When Cole and his teammates tore things up during Survivor Series season last year, they initially made a huge impact on SmackDown. They did go to RAW and Cole had a match with Seth Rollins. Kevin Owens also participated in WarGames last year against UE.
But when they showed up on SmackDown, they matched wits with Daniel Bryan. He challenged Cole in a fantastic contest for the NXT Championship. If they want to, Creative could easily revisit that feud. Having Bryan go through each member just to get to Cole would span a few months at the very least.
Another huge feud that would be looking at the creative team right in the face would be UE vs. The New Day. Kofi Kingston, Big E and Xavier Woods would be down a member but that hasn't stopped them in the past.
Faction vs. Faction is always a good selling point when both groups are among the best in the company. That's definitely the case with Cole, O'Reilly, Fish and Strong and The New Day.
A potential showdown may also force the eight-time tag Champs to find a fourth person to back them up. People have wanted to see the two groups face off and as things currently sit, it could only happen on SmackDown.