I wouldn't worry much about what's sharper than which. They're all plenty good, including the two Mamiya lenses! The classic trio is 50, 80, 150 as you probably know. But you can shift things toward longer or shorter depending on the way you tend to see things, or prefer to make pictures. I did a couple of weeks in Europe a few years ago with only the 120. Worked well. I just got back from Japan with the 40 and 100. I'm not yet sure what I think of that combo. I historically tend toward slightly longer than normal. I'm kind of trying out the 40 to see if I can learn to do interesting things with a wide lens.
Mike Johnston, theonlinephotographer, says "never sell a good lens". You'll regret it.
Mike Johnston, theonlinephotographer, says "never sell a good lens". You'll regret it.