If any blizzard dev is here, please have a look at the response of the following end point. the cards result is wrong…
And btw, the same ‘wrong’ results are showing in your site playhearthstone .com/ en-us/ cards?set=arena&viewMode=table (sorry can’t post links)
Also the arena ids in the meta data is wrong as it provides the same results,
and there is no end-point for the latest set "Darkmoon Races Mini-Set " (looks like those cards do not exist in blizzards world).