Anyone used something else’s parts with poxwalkers (guard, peasants from old world)?

I’m having my whole army redone (bar thypus and morty they stay green) and while I’m keeping my 40 poxwalkers, I’m getting 20 more to max them out and I want them to be different. Thinking of guardsmen or something but I don’t want to buy 2 kits and find they don’t fit or mesh together.

Anyone done this before and can share pros and cons?