I get what you're saying but I just am not so sure anything even worth picking up will pass through waivers. Usually the "worth while" names that do get picked up tend to be guys like Leathersich who basically blew out his arm the previous year and was working his way back from TJS. However, he was a LOOGY not a starter. Additionally, I don't really thing the cubs depth at starter is all that terrible. They still have Dallas Beeler. He's probably a career minor leaguer but he can be effective in a short stint. They also have Aaron Brooks(guy they got in the first trade for Cogs) though he's been mostly hurt. They have Cahill though I think he's a FA after the year. They have Pierce Johnson though he's probably stuck in the bullpen going forward. They have Wood for spot starts though I know he's a FA. And they also have Ryan Williams(not on the 40 man) and Matusz who obviously wasn't good but in terms of depth he could be a guy they might be able to build up over the offseason.
In my eyes, the cubs probably need to aim for a few trades to increase their quality not necessarily their depth. For example, the cubs could probably run Ryan Williams out for 10 starts next year he wouldn't kill them. However, they don't really have an impact guys. That's where things become a bit tricky because usually teams are only dealing guys in the AA/AAA levels for big time trades and the cubs probably don't have that.
Overall though, I get the idea you're going for but I doubt anyone gets cut that really has any hope of starting. For example, the O's didn't cut Arrieta. Jacob Turner did get cut and we all had hope for him but it's obvious now why he was cut.
