They were 11th in the NL in home runs last year with all those boys on the roster. And one home run off of first the year before that with the same cast of characters. I'm also told that the hitting coach last year was unpopular. Point being that if the primary thing you're worried about is home runs(since the team scored plenty of runs, had a high wRC+, etc), the players on hand already are going to make or break that, you aren't going to ship off Schwarber in search of more homers. you're getting caught looking backwards. Bryant is an unknown now power-wise, Rizzo is officially out of his prime, Baez had a career year, and Contreras hit like 7 home runs last year. That's not a guarantee that they'll all be sapped of power again in 2019 but it certainly lowers the odds that you can just count on them to be well above average in the dong department again