By that logic Hyogoro should be a SH since he trained Luffy and added advanced armament which made Kaido vs luffy possible.
And Ussop, Nami should be gone.
Were not analysing how "usefull" a character is, because guess what, all that's negated by the fact Caribou is going to fck over the SHs massively in the story when he divulges to an enemy faction where poseidon and pluton is.
Caribou is a plot point for larger villains, he could have saved all the SHs, it wouldn't compensate the problems he's going to cause.
So low panel apareance, hated by all and gives the most important info in the story to villains.