Yeah good call, I'm actually at the moment pretty optimistic on the pitching situation in terms of just having enough major league talent to cover the innings. Obviously pitchers break, but in a full health situation you basically have:
Assad (can probably get to 150 innings)
Brown (125 innings)
Wesneski (150 innings)
Horton (100-120 innings total, but probably like...60 with the Cubs?)
to cover the 5th spot, spot starts, potential injuries, and the multi inning reliever roles. If you can have three of them on the roster at any given point, it really lessens the need to turn to Neris/Leiter/Adbert (and hopefully Merryweather) night after night and you can let Counsell pick spots. Hendricks and Smyly forcing their way back into the mix gives us a good problem to have.
(as an aside, I'm sure most people are aware of this but I wasn't until this year and it's been a godsend, every time I look at it I see new useful information: https://www.fangraphs.com/roster-resource/depth-charts/cubs)