It's not possible to verify EA accounts currently so the delete option does not work there. I don't think you can remove them on EA's side, either. However the hide option will still work here - and games with 0 achievements aren't counted towards stats.
If I hide the EA Game, will it count towards the completion percentage? I know deleting games on Steam does, but hiding works the same way? There're some old games that I won't be able to 100% on EA and the rest of the platforms because there's not enough people for the achievements.