Thats a fine way to think, in general. But the Jays best players against LHP are not the same as their best players against RHP 1-9.
The only guys that should be in the lineup 100% of the time with zero weight put into their splits with regard to starting are Bo, Vlad, Kirk, Springer, Santander (assuming health), Varsho and probably Lukes. Theur plave in the batting order should certainly change though. Varsho has some split issues, but should probably start the majority of games just because of his defensive prowess and the fact that Straw doesnt really give an advantage against LHP vs him. Giminez has fairly neutral splits, but they're just average, so when a lefty is up and you have a better option that doesn't suck on D (Clement or even Schneider), its defensible to make a switch.
Clement and Barger both have very sizeable split problems that make it advantageous to deploy them more selectively.
The great thing about the Jays right now is they really don't get dominated by lefty pitching so even if Barger, Varsho, Lukes or Gimenez don't start vs a lefty, chances are that lefty isnt going to be around very long and they'll get into the game anyways.