I wish you luck finding your hives. I think you downplay too much most people's fears of even approaching occupied hives, as well as the amount of time and effort and machinery involved in moving that number of hives.
If the thieves loaded by hand, it would have taken them hours, and they would have still needed trucks and/or trailers large enough to haul that many hives. So many hives won't fit in the bed of a pickup at one time. And moving that many hives even with machinery takes time (and previous experience to cut that time down).
As much as I dislike stating it, I think a beekeeper or at least someone with beekeeping experience is your thief.