I like the deal. I'll frame my response by assessing players by their ADP (from fftoolbox) as a baseline.
McCutchen - 5
Molina - 39
Posey - 13
Cespedes - 46
In terms of ADP, the players pretty much come out as a wash. However, like you, I think McCutchen is going a bit too high. Posey is a stud and now that the Giants are doing their best to keep him safe, he represents incredible value. I'm a big believer in position scarcity, so I'd rather have Posey than McCutchen. Similarly, I think people are a little too crazy for Molina. Sure, he was great last year, but he's never had that type of season before and it seems to be a classic peak season for a player in their 30s. I've seen many "experts" rank him in the 100s overall in a draft, so I like Cespedes better. Cespedes, is of course, the biggest risk here. We don't have a ton of prior data by which to evaluate him. Even still, slightly lesser numbers from last year, extrapolated for a full season of ABs look pretty nice. If you'd be comfortable with him hitting .270 20 homers, 15 steals with nice OBP as a baseline with upside for much more, he's a nice fit.
Please help with mine:viewtopic.php?f=26&t=455913&p=3587940#p3587940