So Christian Williams with no Power 5 offers when he committed to Iowa in the Spring of his senior year is better than Jackson who Iowa also wanted?
I don't mean to butt in, but that is on heck of a good question. Which player is better?
First off, I may be wrong but as of the finish of their senior years in high school Christian Williams had enjoyed one Power 5 offer, Iowa. Donovan Jackson, as far as I can tell, none. Now, I hate that term "Power 5", as it is a football term and considering all the excellent basketball schools from other conferences it hardly makes sense in this context.
So let's look at the other offers. Jackson, the only offer in high school that I can find is Mississippi Valley State. I find nine offers listed for Williams including St. Louis, Bradley, yeah a bunch of schools which on occasion get some good players and once in awhile field NCAA invite worthy teams. But you know what, let's just forget about all this for now and look at it another way.
As of 3/16/2015 the day Williams committed to Iowa, Donovan Jackson still had no offers past the old Mississippi Valley State offer! Funny but he was a freshman at Iowa Western Community College, you'd think coaches would have been keeping an eye on him? You know, a kid can transfer after one year of Juco, right?
But, no. Something happened around July, because the offers started coming down like rain the first part of August. 8/9/2015: Creighton, Tulsa, Wichita State (Ok, not "Power 5"...so forget the likes of Wichita State?) Illinois, Memphis, some others. And then two days later Iowa on 8/11/2015.
So what's all this tell us? Not a dang thing. Jackson might have needed to prove he could pass the muster in class, I don't know. But he certainly "blew up" in July of 2015 and the offers came pouring in. Over a year after he graduated high school. Williams, we never saw that "blow up". But then he played only part of his senior season due to some issues with transfer rules in Illinois. We know McCaffery had been watching Christian, recruiting him, for a long time. He obviously waited to offer, but he offered just as Illinois was showing interest.
So, to answer your question, which I think was a good one. I wouldn't be surprised if Jackson has developed some game in the last year. But I also would not be surprised if Williams has a pretty high ceiling. And we couch coaches have no clue who will be "better" when all is said and done.
What these two guys do show, or maybe will show, is that high school players can't be measured by their offers in all cases. In most, sure, but not all.