This is just like the raid, things seem to be going too well but it's not because there's some plan from Oda, he just isn't putting much tension in the manga anymore.
And just like how no one could really beat Kaido in Wano even though his underlings weren't too much of a problem, same in Elbaf, Gunkimu can essentially solo the SHP because no one but Loki is confirmed to be able to even damage him, though probably Luffy will be confirmed as well, but he's still too strong for both of them Imo, and Loki isn't in 100 percent health.
Sommers and Killingham are the strongest GK aside from the figarlands and Gunko, which is why they were sent to replace Shamrock. They're essentially upgraded versions of King and Queen, we already saw how Sommers was a close associate of Garling back in the day, and the only HK who wasn't really just sucking his dick, and we'll probably get similar lore soon about how Killingham was really close to Shamrock, they seem to be around the same age range, and Killingham is maybe the son of the girl HK from GV who we saw with with Garling and Sommers. Oda hasn't had him jobbing yet because he's probably going to be around current Zoro's level, but Oda didn't really hype the GK much because the arc was mostly about Loki, Imu and the flashback, and Oda doesn't really care much about hyping non Luffy opponents anymore, or characters who aren't related to Luffy in general.