100% of Wiemer's value last year was his defense in the OF. His bat has a serious "hole" against MLB pitchers, so putting him at an offensive first position seems backwards. Right now (bat unfixed), he is a good 4th/5th OFer because of his D. If he can hit enough to provide value at 1B, he will have a TON of value in the OF.
Per the OP, I see Frelick-Mitchell-Chourio as the normal OF. Yelich can DH and play LF when one of the 3 sits. There are plenty of ABs to go around there. TT can be the 5th OFer (or perhaps traded). Wiemer to AAA to work on his swing. If one is traded or hurt, Wiemer/Perkins get called up.
Good depth, good upside, good flexibility.