Some energizers have a blinking led that is supposed to indicate when a pulse takes place. They are notoriously inaccurate both in frequency and especially in duration and it's where the misconception of when each pulse takes place and duration comes from. Tho led lighting is faster than incandescent, it still takes a period of time for the light to illuminate and then dissipate, and our eyes' inability to process the images we see in real time is not instantaneous either. The pulses are actually happening slower between each and the duration is much faster than what the light indicates.
We use a 25 mile charger in a 3/4 acre pen over woven wire and a low wire to keep them from rubbing (hair sheep). I'm not sure how well it would work as a 4 or 5 strand fence since I haven't done that but there are others on here that use it and hopefully they will chime in. I have no experience with wool sheep.
It would only be one stand at top and that is mainly to zap anything coming in and dogs going out. The sheep, so far, seem relatively relaxed inside..... So far.
That is the way we do ours all around and it does what we ask of it. This is another case where I can personally say that even the 25 mile charger is not a pleasant experience. We don't have sagging fence from the sheep scratching their hair on it but we give them other scratching posts.