Normally a very good, non-hurting, senior pitcher I would want to be the sole pitcher for me. I know many have made a 1-2 pitcher mix work but many many times it comes along with lots of drama and pitcher unhappieness. But now throw in the sore shoulder thing and it might change my opinion.
Most pitchers are used to a 1-2 or even a 1-2-3 pitching rotation from TB, with the obvious difference being the number of games played in a day. Hopefully both pitchers can play another position and bring a big bat - makes it a lot easier to keep everyone happy! It still amazes me how many pitchers become "pitch and sit" players at a young age......makes for a lot of "pine time"!