I have seen the same thing here. last year 11 different bucks, this year 2 so far. A lot of things in play here. territoriality, pecking orders, does chasing their underlings off to stem inbreeding etc. Food sources is another factor as is water etc.
Make the property as inviting as you can and let them figure out the rest. Cover is one of the single most important things to big mature bucks. Make sure you have a sanctuary for them that you never go in to.