Most of the hoe manufacturers have multiple mounting options. The Bradco 485 on my tractor actually can come as all types. You can buy it mounted it to a trailer frame with an engine with hydraulic pump as a towable. You can buy it with a 3 point attachment. You can buy it as a skid steer attachment for the front of a skid steer. You can also buy it as I did, with a subframe mounted hard on a tractor.
When buying it as a 3pt there is an optional PTO hydraulic pump, because not all tractors have rear remote hydraulic connections. Other reasons to buy a PTO pump is if you need high hydraulic flow to run skidsteer attachments. My hoe works fine on lower flow rates, so if the tractor has rear hydraulic ports then a 485 from Bradco would work fine.
The Bradco 485 also has subframes to mount to many many types of tractors.
When subframe mounted, the 485 is at full strength and can do the best work with the least chance of accidental damage. When on a trailer or three point I think they keep them limited so there is less chance of damage.