Fields - under. If our O-Line is playing well he could scratch on the 4000 yards mark, but I think it will also depend on how much he will come out as a running QB and use his legs.
Dobbins - over. With a QB who is also good using his legs and his developement over the last season he should be able to go over 1,400. Also the RB depth could play a role as I see no other RB in his range, so I guess he won't share carries like he did with Weber last season.
Hill - under. With Olave coming and Victor needing to step up in order to get a shot in the NFL I think the Offense will be split up and not lean on one guy. Also I see a good chance of more receptions for our TE, especially Ruckert, with Fields at QB. But I think that K.J. will be the Go-To-Guy, especially in short yardage situations or big 3rd Downs.