A quick look at recent premiership teams is interesting. There is usually a dominant key forward, a secondary forward (often but not always a tall) and a group of smaller forwards or occasional forwards (eg a ruck who pushes forward or a midfielder). The point is I guess that a goal a game return from a defensive small forward like Mansell, if we extrapolate and give him 24 a year, is a good return. That is, if there's someone kicking 50-60 and a few others chiming in.
2017: Jack (54), Dusty (37), Butler (30), Castagna (26) D Rioli (25)
2018: Darling (48), Kennedy (43), Cripps (38), Le Cras (32), Rioli (28)
2019: Lynch (63), Dusty (32), Castagna (27), Jack (24), Lambert (18)
2020: Jack (33), Lynch (32), Dusty (22), Castagna (17), Bolton (15)
2021: Fritsch (59), Pickett (40), McDonald (33), Petracca (29)
2022: Hawkins (67), Cameron (65), Stengel (53), Close (26)
2023: Mihocek (47), Elliott (39), Hill (33), Johnson (21), McStay (20)
Couple of other obvious observations here too. Frisch had some sort of year in 2021 and the Scats are deep in the brown stuff when Hawkins goes and Cameron's output declines.