The bottom line with big wood is that large equipment is usually used to dumpster/tub grinder it away. If customers do not want to pay for that, they look around for some willing worker or sucker to process it for less.
There is no way to bust up 1000# logs without first quartering it, etc.. They cannot be eased on to a vertical splitter unless you have several strong men. And the splitter needs to be able to handle large oversized wood. I have done well over 1000 cords of wood splitting, never had to face wood this big.
Looking at your pics it certainly looks doable with my equipment, but obviously you have to work with what you have. Have you done a log weight calculator? If its the pieces in the pics they shouldn't weigh 1,000 lbs. If there are bigger rounds then that may be.
For the rounds that I see in your pics, I'd lift them onto my horizontal splitter with my mini and grapple. From there its just rotating them until its all split.
In my younger days, maybe fresh out of high school, I split up some large silver maple with the help of two retired gentlemen. I don't remember measuring the diameter but it was probably 5' diameter trunk wood. I halved them with a sledge and 6 steel wedges, working along the split until it went all the way across. I think I even doubled a couple of them up. Then I walked each half over to a vertical splitter where one of the other guys ran the lever and I'd hand the splits to another guy stacking in the trailer. These days I wouldn't bother with that size wood or I'd noodle it down, but the point being that it can be done.
If you wanted to invest a little bit of money you could pick up an auger splitter, most home depots have a mini for rent with an auger system. Split all of the big ones without lifting, then split those smaller pieces with your splitter.
Here is a link of someone using that setup.
I've not used that myself but there are all kinds of videos online of the same concept, just different power sources.