HJ ($4k) KhJh opens $325
CO (19k) calls
UTG-s calls

Flop ($1,050) 2c3c2h
HJ cbet $550, CO calls, UTG folds

Turn ($2150) 2c3c2hKd
check x 2

River ($2150) 2c-3c-2h-Kd-4c
HJ KhJh checks
Co all in
HJ ($3,125) ?

Co Ken high stakes regular. Very unorthodox style.

What bluffs should CO have here? Given the 1.5x pot, how often does HJ need to be right? Seems like a fold to me with out any blockers to straight or clubs.

Also what is the best sizing to use 3 way on 232cc board given HJ has overall range advantage?