Ngannou arguably scored a draw against the WBC champion, Joshua just obliterated Ngannou. I think Fury trained well for Ngannou, he just didn't take the right approach. Also factor in the pressure on his shoulders. Joshua isn't a past prime, coming out of retirement, fighting above his normal fighting weight Floyd Mayweather vs McGregor. Joshua is in his prime and fighting at his natural fighting weight, if he lost the match there would have been zero excuses. Boxing's credibility would have took a serious nose dive, every past heavyweight champions legacy would have been tarnished, from Joshua to Ali to Dempsey. Also bare in mind, despite how one might view the fight in retrospect, in the lead up many fighters and pundits were picking Ngannou to clobber Joshua. I consider it to be a spectacular, historical performance.
The eye test, it's an unofficial opinion. Ngannou arguably scored a draw against the WBC champion, Joshua just obliterated Ngannou. A few years ago everyone was saying AJ needs to let his hands go and take risks, his past two fights has shown he's taking risks and letting his hands go. At the moment, I think AJ is very dangerous, I think he'd KO Usyk and be in a very interesting fight with Fury. I put Fury as 3 due to his performance against Ngannou. Regarding Sanchez; - he's undefeated - he's defeated a few solid up and comers - he looked better against Fa than Parker did - he's 240 plus pounds of pure muscle, he's got very good boxing ability, he's very quick and can bang
If AJ couldn't so much as drop Usyk in two fights what makes you think he'll manage it in the 3rd? Regarding Sanchez, it's easy to stay undefeated when you're not fighting top opposition. You actually have to beat someone in the top 5 to break into the top 5.