That should pretty much cover you in the kitchen... In fact, with a good gyuto, it could be argued that a santoku and nakiri are redundant.
The only other thing is perhaps a long sujihiki for slicing big roasts, turkey breast, or other slicing jobs that your gyuto is too short to handle.
Maybe a hankotsu which is used to trim and debone meats. The honesuki is meant for cleaning poultry but some people might use them to trim and debone other meats too. They are different in blade shape but depending on what you use it for, you could probably get buy with just the one or the other, or even just use the petty, just being careful not to nick bones with its edge.
Some people might recommend trying a traditional single bevel style like yanagiba, deba, and the like, but those are pretty close to single purpose knives, not much good for multiple things.