I hired a guy with a skid steer to do holes for sona-tubes. 30" holes. i didn't realize how a smallish rock would throw the auger's 'level' off and make the hole go crooked. with the skid steer it was relatively easy for the operator (experienced) to tickle the machine a bit around to keep the hole straight. i'd think that sort of finesse would be difficult on a tractor. I thought about borrowing/renting his attachment to try on my m7060. but after seeing what it took to do a nice hole, i dunno if the tractor is the best tool for that job.
Then there's the hydraulic flow requirement, drain back to the tank plumbing....
All very doable but maybe go see one in operation to see if it would suit your needs first!