My sheep hunting days are behind me most likely
But I've done a lil
The only way to do it is what works for you
Here's what worked best for me
Frogg Togg rain jacket, Red Ledge rain pants
Impertech just too heavy to sheep hunt imo, and this from a guy that practically lived in impertech during September
One thing always in my pack was a silnylon poncho, love dual duty gear, the poncho had tie downs on every corner , so could cover meat in sunny weather, stake out as a tent for a siwash
But what it got used mostly for was keeping me and my pack dry while glassing during inclement weather
With my above rain gear on and pack behind me as a chair, poncho slips over all and did a great job of keeping all but my arms dry ( ( if I was still glassing )
Plus if I'm hiking or hauling meat in the rain I'd rather wear the poncho than rain gear