I don't think it had as much to do with same handiness as with 1) similar size/release point and 2) similar stuff. In 06, both pitchers were mostly fastball, slider, changeup guys with Liriano just a tick harder (God, I so wish he had become the pitcher we expected). I have no idea how much getting 3 at bats against Liriano would help the next night against Santana. I suspect the attack plan for both pitchers was similar as well - get ahead with the fastball, kill with offspeed. etc etc. On the hitting side of it, Morneau has repeatedly said that hitting right behind Mauer allowed him, in the on deck circle, see how the pitcher pitched Mauer and he expected to be pitched similarly. He said it really helped him with LH pitching.