It might take MM+ to get KMarte, but that works, too, if we can get a SP2 for Duran (via 3rd team?)
Alonso & Bregman seem to check the big "clubhouse guy" box, but I don't have faith in Bregman aging well, and he will probably get a 5 year deal. The Sox and 5 or more year deals don't grow on trees, and most have not worked out well. Also, I think Alonso gets 5 years, so 5 years for Alosno, Bregman and a trade for 32 year old KMarte w 5 years left seems almost impossible.
I realize this is just your hope, and I like that infield you constructed (O & D) and the SP'er we could get for MM and maybe others would likely be better than a Duran+ others deal can get us.
Given the idea that Brez will have a restricted budget, I disagree on your B- grade for Alonso, Polanco & Ryan. I'd prefer KMarte over Polanco, but I'd still give that 3 player job a B+ or even A-.
I think we'd be a top contender with Alonso, Ryan and Polanco. 3B would be a worry. Polanco would be, too. I'd assume no Duran to get Ryan, so the O takes a dip a little there, but the two gains more than make up for that. The D is no better with Alonso & Polanco.