Pretty sure this will irritate people, but I just took a look at Jim Harbaugh's stats before he came to Indy and they don't look all that much better than Osweiler's, with the notable exception that Jim was a couple years older and had a more pronounced period of mediocrity before joining the Colts:
Harbaugh:
https://www.pro-football-reference.c...H/HarbJi00.htm
Osweiler:
https://www.pro-football-reference.c...medium=linker-
Jim was a much better leader, certainly, but again, I think we could do worse as a backup than Osweiler