They are going to go where they know, and where they feel safe. I would choose the setup based on a few things
1.) Where you have seen them most frequently
2.) Which is closer to food and water
3.) How the hens have been acting. Take these into consideration. If you say you've seen them on the eastern field then set up there early, and you can always move and run and gun later as needed. Just make sure you've got your turkey vest and box call ready. Good luck,
BigBuck95