I have always had people tell me how polite my kids are. I rarely have to swat a hiney. It's just the fact that they know I WILL if the occasion calls for it that makes it so I don't have to. I can count on 1 hand the number of times each of them has had a whoopin in the past 2 years. 1-2 swats is all it ever takes. Then they're good for MONTHS, until they forget Mom means business...LOL
My scovies stayed in 4 foot fencing & never even tried to hop out. None of my birds hop out except an occasional turkey hen, & then you see her wandering back & forth trying to figure out how to get back in. I just go open the gate & walk her right back in. My anconas & buff geese wander the yard during the day but all we have to do is walk toward them anytime after 6pm & they run for their pen ready to go to bed. Pretty sure all of my birds can hop my fences if they really want to (except maybe the silkies), but the know where the food is & tend to stay put or try to get right back in if they do get out.
Scovies can & will roost if they are in the mood. But they are also fine with sitting on the floor as well. As for pools/ponds, my scovies were the least likely of the 15+ different breeds of ducks I have had to bother to go swimming. Some of them I literally had to throw into the pools to get the mud off of them at times because they just aren't into bathing like other ducks are. They are happy as long as they can dunk their heads.
You should have seen the 2 foot garter snake 1 of my hens scarfed up last year...still alive! You should have seen her bulging crop squirm. I just walked away shaking my head. She was completely fine the next day.
That's possible with only 8 birds, but not 200+