I saw Schumacher's entire career as I did Senna's and Mansell's and almost all of Prost's . I would have to put him behind Senna and Prost ... but ahead of Mansell.
It's a shame that Senna was killed at the top of his game. After Senna was killed there was a void of really top drivers. I'd put Hakkinen as the only other Ace on the grid after Senna was killed in May, 1994...until Raikkonen and Alonso came along in the early 2000s in competitive McLarens and Renaults.
The calibre of driver - other than Hakkinen - wasn't truly great and was characterized by Williams Number 2/Test Drivers (Hill, DC) and Williams Indy Car recruits (JV, Zanardi) and inconsistent Williams drivers in general (Frentzen, Montoya, Ralf) and older guys who weren't on an Ace level in general in my opinion (Alesi, Berger).
DC was sent packing in favour of Indy Champion JV who made a meal of taking the '97 title. Neither impressed Williams and Head.
Hill made a meal of the 1995 season and Williams/Head were already recruiting Frentzen (as early as the winter prior to the '96 season) to replace him. Frentzen didn't perform and was sent packing.
There was a possible Championship in the Williams-BMW in 2003 but Montoya wasn't consistent...and Ralf was even more useless.
Irvine and Barrichello weren't Aces and so Schumacher racked up the stats which were as unusual as the circumstances underwhich they were accumulated ['Special' FIA relationship with Ferrari as confirmed by Mosely; Bridgestone tailor-making tyres for the Number 1 driver of their Number 1 team in their war against Michelins' Williams, McLaren and Renault; Unlimited Budget with 24/7 testing at Mugello and Fiorano; etc.]
In the end, the class of driver now is much greater: Hamilton replaced Montoya; Kubica replaced Villeneuve; Vettel replaced Coulthard...and Alonso and Button both beat Villeneuve as teammates in '03/'04. All of which points to my thesis about how weak the post-Senna driver era was in the mid to late 90s and and early 2000s.