I have had 2-4 hair sheep in a similar sized area for several years. You will definitely need to subdivide the area, and preferably also have a smaller pen or
shelter into which you can shut them in when needed. This will help maintain the pasture, and you can keep them out of one area while newly seeded stuff comes up and establishes, then put them on it and seed the area they were just in. I also cut
hay and make silage from mowed grass and weeds on the rest of my property, as well as
feed them all manner of weeds and prunings. Some breeds are less picky about this than others and that's why I like my hair sheep because they will eat almost anything, like a goat. If you want lambs, of
course, then you need a ram....or the ability to have a ram come visit or take your ewes to have a date with one somewhere. A ram can be big and mean and that's why I am now considering dwarf goats rather than sheep, just to be able to single-handedly manage them....