He's too small. This the same thing we saw with Luka. Cory is a good on ball defender when going against similar sized players. Then his backup is 180 pounds of SF. The only thing keeping them in this now was Whiteside going full Shaq mode inside.
Again, this dude still for some reason hasn't figured out the small ball thing. Keep as much size on that wing as you can so you can switch. It's not rocket science. The Suns were running 6'6" 6'8" and 6'8" back at the Kings. Maybe there is a benefit to 3 PG's but who's going to shoot it?