I think top end starting pitcher is the biggest weakness. We just don't know about any of these guys other than probably Gray and maybe Ryan and Ober. But none of those is elite.
LF is fine. Any issues there are short term. 1B? I'd consider Larnach there, but his arm has been surprisingly effective in LF. Arraez is fine there.
Really, 3B is the biggest issue, and if the incumbent doesn't hit, Lewis should be there this year.
If you look at the bad teams, there isn't much the Twins could use.....other than Montas, imo.