For anyone interested, here is the link to the Main Article talking about the "Too White" problem in Arknights and many other Anime games :
https://cinemandrake.com/arknights#toc9
Strangely enough, despite him bringing up Uma Musume, I personally don't care if there is no POC representation there because I am not interested in that game by the way, because even with predominantly light skin all the characters in that art-style look too bland and same-faced IMHO so I'm not sure adding dark-skin characters would help make them look not too same-faced as the rest.
Ay least Arknights, Honkai Impact and Azur Lane have more variation in the character designs.