Kishi nerfed Madara a lot is why, I don't see him using Zetsus but actual dead shinobi's that he gathers and imbed with his chakra rods. He could have taken the dead mist anbu that Obito killed and used them as his 6 paths, one of the summons repairs the paths bodies when they are damaged so fixing them wouldn't be an issue. Madara could have used the path path power after he got his second eye, he had chakra rods in Hashirama and Tobirama so all he had to do is remove some so they could move and control them as his paths since Nagato showed that he can use any number at a time and after Jiraiya killed the summoner and transported his body to Konoha via toad, Nagato simply replaced it with another body.
We see Obito using the 6 path with the Edo Jins and he didn't split his powers with them, in fact they were using their own jutsus which shows Nagato being nerf since his paths couldn't do this nor did Nagato used any element jutsus even thought he could use them all when he was a kid. It doesn't matter if the person you use as a path was weak alive, they get powered up with the Rinnegan which give them shared vision, enhance vision, can use chakra rods as blades or to disrupt a person they stab chakra flow, and have the chakra of the caster in them. This is Juubi Jin Madara with an enormous amount of chakra and he can use them in prefect unison as Nagato did which allows them to attack with great precision, evade counters, and counter attack themselves.