Someone is going to need a day off here and there. I think the daily starting OF will be Chourio/Mitchell in CF with Yelich in LF and Frelick/Chourio in RF. Then when Yelich is the DH Chourio, Mitchell and Frelick will be starting in the OF which is about 50 games. You only need to find about another 100 games for the other part of the equation. So lets go conservative here and say Frelick gets about 30 games at 3B that means you only need about another 70 games from him to play in the OF to get to 150 games and the same for Chourio and Mitchell. Chourio and Mitchell will probably get one or two games at DH also. Lets say that is just one game for each at DH.
It is not that difficult to get to 150 games played for Chourio, Frelick and Mitchell. I think Mitchell gets about 3 games a week starting in the OF and 1 game where he is used as a pinch hitter. Also games are not really all that important it is PA's that are far more important and I believe there are plenty of PA's to go around for Chourio, Frelick and Mitchell to get about 450 PA's each which is about 140-150 games played.