How many drafts do you have?

How many horses do you have on how many acres? I have 2 draft(1 retired and one 5 year old) on 4 acres. I have had a deal of a lifetime given to me but I'm not sure my pasture can survive.
I have the 2 drafts and have the oppurtunity to get a team of well trained drafts with everything to drive them.
As I stated I'm worried about the pasture, my guys are on 24/7 turn out and the grass is short, could my grass survive if I was to keep everyone is a smaller section at night and let them out in the morning? What do you do to keep up the grass?
Anybody have any tips on thickening a pasture?

Usually it's one horse per acre to keep it growing. Not sure if that changes with draft horses.

I have an acre but it's dirt 'cause in CA there's no rain!

I'm not sure if it changes for drafts or not but I always was told an acre per horse. I have my paint mare, my mini colt and my brothers temp. Palomino gelding on an acre and a half. And amazingly my grass is doing pretty well (this is the only year I have had any luck with my grass though). During the day (12 pm-6pm) I let them in my fenced in yard which is about 1/2 an acre and then at about 6 pm I put them back in my field. I hope this was of some help :)

1 draft to myself, but she is in a smaller pasture with 3 other drafts. We just sectioned off an area to plant new grass through fall and winter, and spring. When that gets growing, we'll open it up to them and section off a new area to grow. We're in California, too, so it takes a lot of watering.

I have 1 draft cross and 3 Haflingers on about 10-15 acers 24/7... I think (it changes with which gates we have opened.). We haven't worried about thier grass at all. I think you'd be cutting it close to have 4 drafts on 4 acers 24/7, even if they weren't out 24/7 I would feel like it'd put a real strain on the pasture. I'm not sure if splitting it up would do any good, most pastures would need more than a night to 'recover'. But you could try it.
I'd have a hard time passing up a good team!! It is a hard decision, good luck.

None at the moment, but hopefully soon!

One draft and her day turn out is with 5 other horses on about 2 acres. She's the only draft and she's let out with a bunch of pony mares that hate her until she butt bumps the apple tree and then all of em love her. Surprisingly the grass is still green and enough to graze on for all of em. The whole property though has 40 acres and the horses are routines switched to experience other pastures