What don't you get? They are loading on up prospects? They have 3 of the top 6 or 7 guys on most lists now, plus a whole bunch more. They probably have the #1 farm system in the majors after this deal.
Signing the Shark didn't make sense from a Cubs perspective. He is 30 years old right now and the Cubs are probably 2 years away from being a team that is expected to be in any sort of race. Giving him a 4 or 5 year deal when the Cubs are expected to be bad through at least next year is bad money, especially when they can land a top prospect in MLB.
From a hitting perspective, they are ridiculous in the minors, not so much on the pitching side. It's now a matter of time before they flip a prospect or two for a front line pitching prospect(s), but I don't think there's much doubt that there's a ridiculous wave of talent that will be coming over the next year to Wrigley.