The problem is something that has been the Brewers' postseason achilles heel in recent years, though - their position player roster doesn't have enough offense.
When Mitchell kept getting hurt, with Yelich needing time out of the OF, Chourio dealing with hammy issues last season and missing time, a player like Perkins is valuable to help a good team churn through regular season wins. However, if those players + Frelick are healthy and producing at reasonable levels, Perkins is a 6th OF on this team because of defense only, and he's worthless in October. Arguing that 1 good defender with a weak offensive game doesn't crater a team's winning percentage too much is kind of silly, when the rest of the roster is pretty damn good. It avoids looking at what the teams winning percentage could be if that roster spot was manned by a player who could provide what has been a problem for this organization leading to playoff exits and the few tough stretches during regular season - offense.
The same can be said of their IF left side options right now - Pratt, Ortiz, Hamilton....all plus defenders you can put across demanding IF positions....but they are bottom of the order hitters on any MLB roster that can be upgraded with a better hitter who may not be as slick defensively but can still probably give you a better chance to win a game for you in October instead of just being a postseason run preventer behind a pitching staff that already will be striking a ton of hitters out.
I'd much rather add a bat-first OF/IF option to this roster and option Perkins to AAA.