I have a few thoughts:
- have you seen poly wire? I would use a hardwire for perimiter but then if just going with step in posts the poly wire is very easy to roll up on a spool and move.
-10 feet seems very narrow, even if it's just the sheep 10' seems very narrow
-the pictures give me a good idea of what is in your mind but what is in my mind might not work as well:
My idea for your pasture situation would be to run one center laneway (build it up with some driveway mix about 8" deep) then split your padocks off of that into probably 4 or 8 sections (either 1 acre or 1/2acre aprox)
At the top of the laneway you will have your main gate, as well as your water tub. Then a few slinky or bungee gates (i really like the bungee gates since they don't tangle like a slinky) close the horse & sheep out of all but one section and rotate through.
You will quickly be able to figure out (partially depending on rainfall) if you need to move your animals to a new section every 2 days, ever 5 days ect...
I would definitely keep them from getting it too short though, some people deffinition of "my horse ate the pasture down short" varies, if rotational grazing I would pull them out when the pasture is down to 3-4inches tall and move them to the next. If I remember correctly the ideal height is 6-10" of most pastures so the grasses are still good but pulling them out before they do damage
You might also need to go through and clip pastures right after you pull the horse out so the whole thing grows at a uniform height
Yes a lot there, probably won't go quite that technical but just my .02 to make the land work the best and get the most out of it