Id rather we add a SP to force a demotion of one of those 3, and I really dont think any of them deserve a emotion, but someone will get hurt, and if we have to do it, it would only be because the guy we added is better, equal or can pitch more IP as a starter.
To me, having a solid 13 is great, but #14-16 scare me bigtime. We've already used 25 pitchers, which is nearly double 13. We've used 21 pitchers for 9 or more IP. 18 pitchers have 14+ IP and Sandoval is the guy with 14. He's projected to reach 50+. Guerrero is at 24 and could reach 40-50.
Add a SP'er and find a way to make it work. If a really good pitcher has to be demoted for a few days, so be it.