The paint ball idea is a good one. I used a paint spray can to finally show a neighbor his collie was over here all the time. I do give folks warnings, if they are neighors, my problem is my dog shows no mercy herself, so there isn't alot to give a warning about if they cross her tracts, are too close to her baby goats, or especially her hen house!
It will be hard for you in the beginning because when you do start with your guradian dogs, they will be pups themselves. I was lucky that when we purchased our property the other places that went up for sale didn't get moved onto for about a year, which gave my dogs (I always keep Rhodesian Ridgebacks and crosses of) a while to grow up. We have our share of pits, rottwilers and other strays that are buried in pet cemetary, mostly by the dogs, some by a 22.
Check out your laws. Although we don't have a leash law in San Jacinto County, we do have really good animal laws. It only takes one judgement (in our case a drunk neighbor shot a pig of ours) for the neighbors get it really quick they can't afford to replace your stock. I didn't take the judgement from the guy, I did tell him that he was lucky this was just a pig, had it been one of my goats the difference in money would be quite substancial, I just wanted to make a point. It makes it nice when your neighbors are just a tiny bit afraid of you also
Funny how you move out to the country, and coyotes, bobcats and fox, although they are around are not the problem, it's strays and your neighbors pets.
You do need to buy a few guardains, start them off away from the main fenceline until they are older. I prefer Ridgebacks, because they are not only excellent stock dogs, mine help me clean babies and everything, yet patrol all the property, and stay with me doing chores, greet company, and really seem to know instinctively who belongs and who doesn't.
I think the 3 S's, originated in Texas