If Stanton/Judge/Harper are all healthy and playing in an AL stadium, then they divvy up RF/LF/DH. If one of them is injured and they're playing in an AL stadium, then Sanchez can DH.
If they're playing in a NL stadium (which only happens 10 games during the regular season), then either Harper can play CF or one of them could take a game off. It's reasonable to think that at least 1 of them will be injured sometimes (perhaps 40% of the time?), meaning that there would probably only be about 6 games during the regular season in which Harper would be forced into playing CF in order for everyone to be in the game. Harper could play all 6 of those games at CF, or he could play 3 games at CF and he, Stanton, and Judge could each take 1 game off during the other 3 games and just have Hicks in center.
Harper is plenty athletic enough to play CF for a handful of games per year. And those regular season games at CF would be worthwhile practice to prepare for World Series scenarios where he could play CF in the national league parks.
It's not hard for people as talented as Harper/Stanton/Judge to shift from RF to LF and get good at it. And it's certainly doable for someone as talented as Harper to play a small handful of games per year in CF, especially considering the extra rest his legs will get from being able to DH once or twice a week.
There's plenty of playing time to go around, and I think the Yankees will be willing to throw the biggest money at Harper and Machado, so I think the only real issue is whether Harper is willing to split time between RF and LF and perhaps play 5-6 games per year in CF (maybe 8 or 9 games if they make the World Series). If I were Harper, I wouldn't have a problem with that; the fun and benefits of playing on such a great team (for half a billion dollars!) would far outweigh the drawbacks.
2019 lineup
Machado
Harper
Judge
Gregorius
Stanton
Sanchez
Bird/Austin
Hicks
Torres
RIP mags
