Well you could always leave Borisc out for Chapnis/Payne, but the only reason you're not doing it is the fact that he's a better bowler than them anyway. He's a bit of an anomaly for that reason.
Just because our bowling goes from 33% bowlers to 40% bowlers doesn't make the unit itself stronger !
I'm pretty sure I'll leave Force in irrelevant to this anyway. I'd like him to get at least 2 more PCDIY and one more ALC game + I want to give Logan/Lee/Das another chance to make the decision as to who is dropped easier.