Yeah, you kind of answered my question in the other post you made while I was typing it out. Assuming the Brewers are using analytics, the strikeout rate combined with the high BABIP may show that it will be tough for him to repeat last year's numbers.
that's not to say that he can't cut down on the strikeouts. Kris Bryant has managed to cut his rate from 30.6% down to 19.2% (which is below the league average) in a two year span.
it is possible they're skeptical on Santana and the rest of their young outfielders, and they figured they'd remedy that by bringing in two long-term answers in Cain and Yelich.