I know zero about hunting fields...
But, I have to guess with a group of hens that size that there are probably some other bachelors (beaten into submission) around waiting for an opportunity on those hens...
I might try setting up on the edge of any woods bordering the field one morning try to call in a less dominant (more quiet bird) and watch where the bird you are hunting enters the field (to hunt him the next morning).
Guesswho is right... That is a tricky situation... I'd put out a bunch of hen decoys with a Funky Chicken were I to go straight to the field hunting...