They could be carried around in big tubes on trucks but were loaded into silos for launch as they are fixed systems designed to defend fixed structures... in this case Moscow.
The S-500 is a mobile system likely intended to operate with S-400 units, though it will likely not move around in operation... unless they mount one on a train with the new train based ICBMs.
I would expect the Nudel to be truck mounted but launched from a silo, so I would not call it a mobile system... could be wrong, but most of the infrastructure the Nudol operates with is the Moscow ABM system and is fixed so it wont be all that mobile even if truck based.
The S-500 will likely be fully mobile like an S-400 battery is fully mobile.
In fact an S-400 battery would likely benefit from improved sensors from the S-500 battery and vice versa.
The Nudel evolved from the Moscow ABM system while the s-500 is a from scratch system likely based on the S-300 or S-300V and using S-400 technology and is probably a multi stage missile. I doubt there is much similarity between Nudel and S-500. They might look similar, but it is like the T-80 and T-90 which evolved from the T-64 and T-72 respectively... they might look similar but they don't have interchangable parts...