Need advice with metal on metal conversion/kitbash

[Scalenex]

I have a plan to make a Skink Priest mounted on a Horned One because I have a surplus of old school Skink priests and Tichi’s Raiders.

I cut the torso off a rider and cut the legs off a Skink Priest.



I thought I could glue them together and then mold the blend with greenstuff to smooth it out but gluing the legs to the priest torso is an ordeal. Any thoughts? Do I need to try to shape the metal? Should I try to hold in place with molding?

 

[Old Mossy]

Drill and pin with some brass rod. Sculpt some detail in over the gaps. Success.