I think Daboll did ok with a developing QB that is hardly a finished product, one capable RB (which really limits what you can do offensively), nine new starters overall on offense (which was a headache all season), a rookie as your top TE ( who can be a monster), no reliable number one target at WR, the continuing revolving door at RT, the OL as a whole playing severely banged up all year.
Did I miss anything?
All in all, with the right off season additions, the Bills could have their best offense in years and Daboll will be the beneficiary.
If it fails, Daboll will be the 2020 scapegoat.