John fleck is the obvious answer
Jake Wright was also amazing last season and as you say Duffy did really well.
From last season Carruthers, OShea, Clark and Hanson all played a part in the promotion push as well.
Championship reserves was also fruitful for Wilder in Moore, EEL, O'Connell, Lafferty and Lavery
Looking at that list, it just shows what a terrify job Wilder di8d in the transfer market last year, only Hussey (that can think of) didn't really perform when required to. Wilson was perhaps also not a significant player, but in my mind he did OK when fit and played, he just couldn't get in the team.