There's your issue right there. Despite poor planning in buying goats/jack and deciding to keep them together (or whatever management issue is going on), the biggest issue is the word CANNOT. There is no such thing in paddock management. Same goes for pasture management, and folks who tell me they simply CANNOT make a sacrifice area for their donkeys (dry lot) so they won't founder. Or they CANNOT find a way to separate the donkey and the horse at meals, so the donkey is getting obese stealing the horse's high energy feed. Oh, there's a million other examples.
The word CANNOT rankles me in these situations, because as the human who brought these various and sundry animals into your life and onto your property, YOU are solely responsible for their wellbeing. If you cannot care for them properly, then I suggest not owning them. Sound harsh? It isn't. These animals depend on YOU to survive. I cannot tell you how many times my husband and I rushed out to get electric fence wire or a gate, or extra heated buckets, or nails, or posts.....because we had a slight management problem. And believe me, we are on a shoestring budget. There are ways you can afford to make management more manageable. All it takes is a change in attitude.
Forget your human concerns for a moment. Forget that you'd like things to look a certain way, or that you want to afford that next vacation/latte/meal out. Your first responsibility is to those creatures under your care who depend on you. Forget that it is pitch black out, in a snowstorm, and you can't feel your toes. Forget that it'll cost you extra and that you'll have to drive through hell and high water to get the parts you need. If they need something done safely so that they can stay comfortable and healthy, you DO IT.
I would say about 99 percent of the times I see a panicked person writing about a management situation, it could have been prevented with research and proper planning. That also rankles me a bit. But I admire those who realize they have made a tactical error and decide to immediately rectify it. Those who whine that it would be too hard or cost too much need to figure out a way for it to work. There's electric wire and tape, which'll work in a pinch. There's panels you can buy to make extra areas.
Now, there's one caveat to this: I DO understand that there's massive amounts of misinformation out there. So many people think it's ok to house donkeys with goats/cows/(whatever animal the donkey might attack). Sometimes donkeys do ok with those animals, many times NOT. Or, because they saw cute pictures of dogs and donkeys laying together in the sun that any donkey will be ok with any dog. I think it is super important to realize what we are up against in the donkey industry. A whole lot of myths that get new owners into trouble they didn't need.
I will challenge everyone who reads this to think about what CAN be done to make their management of their animals WORK for their animals. Forget the word CANNOT.