No law says Nagato has to be stationary to use the Preta Path. A coincidence proves nothing, Nagato was always in a situation where he could afford to remain stationary while using the Preta Path.
Nevertheless, you don't need immense focus or need to be stationary to use the Preta Path. Pain never really did, nor did Madara... Nagato casually absorbed Naruto's Rasengan while pulling out his soul.
Nagato kicked out the notion that you can use one Path at a time, so he could theoretically be near invincible as his constant Preta Path barrier would force one to go into close combat... Paths like Demon Realm, God Realm and Human Realm make that a bad idea.
Also it is heavily implied that anything Itachi can do with his MS, all MS users can do. That has implications for Madara as well. It is probable that Tobi's fan feat can be directly generalised to Madara too.
The fan and Susanoo's slashes are two things which may ensure Madara doesn't have to necessarily enter close combat.
Chakra attacks like Mokuton are a silly thing to use as all they'll serve to do is increase Nagato's chakra capacity whilst decreasing Madara's.
