There is an obvious list of possible conflicts coming at once at Hyundai:

What if he wants changes to the car that go opposite to Neuville and that can't be done without homologation jokers?
- a) Probably he will have the last say as reigning world champion. But what if that makes Neuville and Sordo much slower and therefore threaten manu champ?
- b) Or what if the changes are not really possible without changing the whole car? This applies especially on tamac as shown by Loeb/Mikkelsen

Let say no (drastic) changes are needed at start. It's still quite likely that Neuville will be as fast or maybe faster in first few rallies. But it's unlikely we will start to see strong n1 prioritizing at once, but that can in the end hurt the chances both have to the title as Ogier will benefit.

It might be that he only agreed to join if he is clear n1 from start, but b) could still be a problem.

For team dynamics it will be interesting.