You can and they probably will maximize how much they all pitch. The good news is for this to even really be a problem they would have to start making it pretty deep into the postseason. There are also so many off days in the postseason and the big three are fairly interchangeable when a new series starts you wouldn't feel obligated for like Burnes has to suddenly be pushed to the front of the line on 4 days rest. Though maybe they will opt to maximize Burnes/Woodruff/Peralta, in that order. The Brewers aren't going to toss Brett Anderson out there over Burnes, because Burnes needs a 5th day of rest. When I say every fourth day, that’s 3 days of rest, which none of the Brewers starters has done this season. In a 5 game division series there would usually only be one off day between the second and third games and one between a fourth and fifth games. So, start the top 3 in some order in the first 3 games and go from there. If you get to a fourth game, the choices would be a fourth starter, the first game starter on 3 days rest, or a full fledged bullpen game. Depending on how much the bullpen had to be used in the first 3 games, and whether you are ahead or behind 2-1, I think a manager would at least want the option of a fourth starter. Which is why I think you have to have four starters on the roster.