I personally disagree.Don‘t take those stats serious. According to them Diantha is just one point behind Leon, but we all know how their match will turn out.
I think the STATS are actually a very good representation for the four of them.
We see Leon with Perfect Attack, Defense, Speed (With the other Regional Champions having gaps in 1 or 2 of these traits). Makes sense as Leon being the unbeatable champion would have no gaps in this aspect. Plus, Ash has never been a defensive trainer and has mostly been about Speed + Offense. He always wins his matches with most of his Pokemon falling; so makes sense why he seems much weaker in Defense compared to Attack + Speed.
As for the strategy debate, as stated previously; I think this more has to do with conventional game tactics which Ash barely uses in contrast to the other Regional Champions.
And for the surprise/Unexpectedness trait; this has always been Ash's ace right from the start of the series. And Cynthia's low rating here also makes sense given that she's the most experienced trainer of the bunch. Someone as experienced as proficient as her, would be less likely to resort to high risk unexpected tricks.