Even though I like the three God's Knights so far, the problem with them is that for now they don't feel like huge threats.
Last arc had tension from Kizaru as well as the Five Elders.
Hopefully things will change later on and Oda hypes up Sommers, Killingham, and Gunko and actually makes them a huge threat, or at the very least he has Shamrock return with more members of the God's Knights.