Nank to me is like an in between version of Soldo and Chol. He moves around the ground and is versatile, chases and tackles hard, kicks goals. whilst he is well built enough then he can generally hold himself in the ruck - though struggles against bigger opponents in tap outs. Soldo is a classic ruck, strong and physical not easily pushed around and wins his fair share of taps outs; he also chases and tackles more each game he plays. Chol is a string bean at the moment however agile, skilled and smart, and kicks goals - much less physical right now as he does not have the physique. They all balance each other well.
I believe we have the luxury of playing any 2 together and it would work. The notion that Nank and Soldo cannot play together is a furphy to me.
Nank being out has provided a surprising positive insight of what Soldo and Chol are capable of at AFL level - and it seems to have helped their development enormously in a short period of time.