That's one of the reasons I never liked my in-laws purchasing wood from them.... it was a mix of 16-24" wood. No uniformity. Their wood stove is wide, so 24" is no problem for them. I would need 16" for mine. I don't recall the splitter they use.
There's another tree service a mile south that has a processor, and a conveyor to pile the splits up. Again, one guy splitting anytime they aren't on a tree job.
If you have someone always splitting when there's downtime, even if it's not a full cord an hour, even half a cord an hour, paying someone $15-$20 an hour to generate $75-$150 an hour is still a good use of his/her time.
It's also a way to keep a good man working rather than send him home because they don't have other work for him.