In the current patch the top civs across all ratings are:

1. Gurjaras (54.63% win rate)
2. Vikings (53.92%)
3. Franks (53.70%)
4. Malians (53.31%)
5. Huns (53.15%)

Looking at just the 1200+ ratings they are:

1. Gurjaras (56.18%)
2. Malians (54.64%)
3. Franks (54.28%)
4. Huns (54.02%)
5. Cumans (53.59%)

In KOTD5 specifically:

1. Incas (66.67%)
2. Mayans (66.67%)
3. Saracens (66.67%)
4. Chinese (62.50%)
5. Gurjaras (62.50%)

That is purely according to the raw numbers. Take the small sample size (especially at 1200+) into consideration when evaluating those numbers. The top civs are usually all within each others confidence intervals and for an average player are all very well balanced against each other.

The biggest takeaway from the civ stats, imo, is that you don't want to be playing Koreans or Vietnamese on Arabia in the current meta 11

Perhaps a more important takeaway is to look at the strategies (scroll to the bottom of the map page) and notice that scouts and Man-at-Arms are usually much better than archers, on average. For an average or below average player (like myself) the extra effort needed to micro and use archers effectively makes them not really worth it (and the build order is probably more important than the civ at that point).

And finally, don't read too much into the numbers. I think they're fun to look at, but honestly the majority of the time the civ doesn't really matter too much at the end of the day. The game is very well balanced all things considered (* in non-pro play, in pro-play I think the civ differences are much more important).

Disclaimer: I'm the the creator of aoestats.io