Of course brother love to offer advise to people that are open too it. I’m a climber and operator for a production tree removal company. We have a few Vermeer sc-552 they are big and are monsters for stumps. Find someone with a similar sized machine and get a grinding quote, then find someone with a mid sized excavator, a mini excavator in my opinion won’t be efficient time wise, it would get the job done but would take a bit longer. Mid-size or bigger is the way to go. Anyways… find someone with an excavator and get a quote for popping all the stumps. Then chew over the professional grinding cost vs the excavator removal cost vs your time and frustration in grinding and removing grindings, plus cost of buying a relatively pointless walk behind baby grinder.
How's come none of you bright guys recommended renting a good grinder for a day?
I can run down to the local Bandit dealer, pick up a damn good stump grinder for about $400 per day, and knock out an army of little 14" stumps. About 45hp, I don't remember the model number, but the hydraulic drive was reliable and strong, and the track drive was not at all likely to get stuck or roll over.
I'd guess it would do a 12" pine stump in less than 10 minutes, possibly only 2 or 3, depending how deep you want ground, and how many roots you chase.
I've even rented the machine for a good day's work, even though I already own a stump grinder. My little Rayco 1625 is ok, but not so good when you need more production.