Anyone have the same size head as Defensor?

I'm looking to customize my PotP Inferno and some extra CW figures into an original combiner.
I want to know if there is an easy head-swap I can do for the combined form. Are there any known figures with heads roughly the same size as CW Defensor, with downward-facing ball joints of the same size?
I want to know if there is an easy head-swap I can do for the combined form. Are there any known figures with heads roughly the same size as CW Defensor, with downward-facing ball joints of the same size?