From what I have seen, I don't agree with this. Williams isn't a known shooter and isn't going to beat people of the dribble. He is better served in the post of offense where he can clean the boards. I hope he develops a 3 point shot like Biggie and can steal 3-6 points a game that way.
Dowuana isn't an outside shooter. He has some very nice touch near the rim and will be a dominant scorer. At this point though, he isn't a rim defender. He isn't afraid of contact though, which means he could easily develop into one. Dowuana has tremendous upside and could end up like JJ with a very nice midrange and see dramatic improvement every year. He is fairly new to basketball and eager to learn. I love this pickup.
I am thinking Castleton would have been a slightly better fit in that he already has an outside shot and he already is more of a rim defender. That means that early on, he fits PERFECTLY with Williams as the 4. This year's team will generally have 4 deep threats on the court at all times. Next year, it won't be that way if you see Williams and Dowuana on the court at the same time. If Purdue had Castleton that could seemlessly switch who was in and out of the post and still have four shooters on the court.
Here is the caveat. We don't know yet what we have in Haarms. Haarms may end up playing the stretch on offense and allowing Williams to play the post. Williams is quick for his size, but if he is going to play four on defense he will need to work hard to continue to slim down and get stronger. Williams seems like such a great kid though, I don't think it will be a problem. Dowuana may be used like Haas for the first few years by coming 10-20 minutes, come in and give the other teams fits on defense. He will have very good numbers and lots of opportunities to improve just like Haas.
We really needed two big guys in this class and I am glad we we're able to land Dowuana. I love the upside here. He could be exactly like JJ in the future. I can't say enough good things about Williams. I was just as excited to land him as when Purdue landed Eastern last year. I am not sure what Taylor plans on doing next year, or what Purdue has in Ewing. But, now Purdue has three young big men with all kinds of upside and they all three do very different things. Although Castleton might have been a better fit immediately, Dowuana has more upside. I think that is the reason to be excited.