Playing devil's advocate here. ...
I think Joerger likes Bags off the bench as the main scorer on the 2nd unit, replacing Bogs in that role. I don't mind it, because off the bench, Bags will be more able to alpha dog it as a 1st option.
Now that I typed all that out...
I totally agree with you that Bagley should start and Barnes should be our 3! But ah well, as long as Joerger wants to do this, might as well squint and try to see how it COULD work.