My understanding is that multiple flock guardians are only really needed in areas with serious predators...wolves, brown bears, puma, etc, not so much coyotes. While coyotes have taken on eaten lone large dogs, they haven't been successful against lone working flock guardians.
A flock guardian and a more herder type dog or pair of herder type dog may be your best mix. In fact a pair of herder types may be all that is needed. Note that many of the herder breeds were also expected to be protectors.
I think the Border Collie is the best dog...for herding certain breeds of sheep for flocks of a certain size over certain terrain types. They are great dogs but even working lines are not the end-all-be-all of farm dogs. As far as farm work they are very specialized and may not be your best choice.
I think some of the more generalist breeds like the Australian Shepherd or English Shepherd may be better choices. Even better are the generalist 'old time farm shepherds' aka 'old fashioned scotch collies' who were the landrace that the Aussies and Englishes came from.
These dogs are herders and guardians, but above all else they are mind-readers. By that I mean they are often spooky-smart and in the same way that identical twins will finish each-others sentences and thoughts, so too will the Scotch Collie, knowing what you want done and doing it before the thought fully materializes enough to be given as a command. Scotch Collies have been known to simply pick up so many words that owners actually spell things out on occasion to keep the dog from hearing the word and reacting. They can figure out what their human is going to be doing by what shoes they start putting on. They have been known to figure out 'laundry day' and while the owner pulls off dirty sheets and tosses them on the floor, the dog will drag the sheet bundle to the laundry room...untrained, just through observation of the work routine of the home.
I suggest you read these two testimonials from pups sold from one of the few Old Time Collie breeders https://glencraigean.wordpress.com/2013/11/30/247/ https://glencraigean.wordpress.com/2...l-about-cyrus/
Here are some breeders Heritage Kennel, Old-Time Scotch Collies, Tucson, Arizona https://glencraigean.wordpress.com/ https://4jacres.wordpress.com/puppies-2/
Even if you don't go for the Old Scotch, and decide to go with a Border, Aussie, or English, I strongly encourage you to go from farm working lines. Here's a great site for that Farmcollie Breeders | American Working Farmcollie Association