Hiring thugs or however are called these days is a very dangerous move, what makes you believe the same thugs won't turn on you if they get a better offer from the squatters?
I believe this is a matter of land owners defending their land, hiring mercenaries don't ever work out like in the movies, the only way out of this , is getting together with other land owners and creating a neighborhood watch, now, with that said, there might come a time where you as a land owner will have to get your hands dirty doing it, so the question is, how far are you willing to go to protect your land?
Squatters know they have nothing to lose and you have everything on the line, including your freedom. Tough decision to make, but if you do nothing, the fate of your land is sealed.