They brought Penny up so he and Zito could swap Alyssa Milano stories!
This is one of those times where I think you (and by you I mean a fan, not just singling you out) may be reaching for straws in an attempt to justify a roster move...
Pretty sure the reasons for signing Penny were as follows:
-He's had success in the Pen before
-He's had success in SF before
-Vet presence in the Pen that isn't of AAAA variety
-He throws 95 coming out of the pen
-He was free and cost the team nothing but a league minimum deal