Your best approach is probably transitional.
Poults not reared by a turkey (i.e. hand-raised) are not too bright, and have a tendency to commit
hari kiri in the first 7-8 weeks.
A
tractor works well after they get the hang of staying alive in the brooder, but again, it's a transitional stage to get them used to foraging, seeking shelter from the rain, etc.
Once they get bigger than a standard-breed hen, it's probably safe to day range them, penning them in at night. Details of note include that land-based predators prefer prey they can easily dispatch and carry off, so they prefer pullets to hens and hens to roosters, so once the turkeys are bigger than the balance of the birds you've got around, you're unlikely to have issues. At the same time, a 10# raptor isn't going to try and carry off a 5# bird and risk not being able to get off the ground if there's a 3# bird available. As soon as they're feathered out and have figured out flying, noctural predators shouldn't be an issue because turkeys will go as high as the opportunity (and body weights) permit. At 20#, my last two toms were flapping through a near vertical 5' jump to roost to top of the hoop house that serves as my
chicken coop b/c my roost bars were too high to allow them to avoid hitting their heads.
To avoid them going feral, or wandering off for too long, I'd suggest that getting them used to treats at bedtime is a good idea. Go out about an hour before dusk starting when they're still in the tractor and giving them treats. When you begin ranging them, start slow, with a couple hours in the afternoon, followed by treats at roost time, so they get in the habit of coming back to the same roost at the end of the day. Then you can just start easing them into longer and longer range days until they're not actually penned in at night at all.
I wlll point this out. Because it sounds like line of sight may become an issue at times, I would strongly encourage a very loud vocalization on your part as part of the training regimen (I used a high-pitched "turk turk turk") so that when they're out in the brambles eating
rose hips and chasing rats you can still get their attention.
Beyond that, the only other consideration is going to be breed choice... make sure that if your adult birds are going to be free-ranging that they don't look too much like the indigenous wild birds in the area or you may accidentally lose some during bow season.