It would appear that flagging them doesn't always work. If one gets uploaded again make a post here and it will be dealt with. I've sent grafzyx a PM though, providing him with a link to the FAQ and quoting the necessary text regarding both the wiki and official images in cases of multiple artists sharing the same page. Hopefully he won't ignore it like he did my shout here.
Oh and I got rid of the official image by contacting a mod (if multiple artists share a page then official images aren't permitted). If one gets uploaded again then someone should flag it, pointing out that there are multiple artists called 'ZYX'. Although hopefully he'll see my shout, realise it's not allowed and won't re-upload it.
@grafzyx: Whether they were earlier or not is irrelevant. The rules of this site state that if more than one artist shares the same name, the most popular artist in the charts over the last 6 months have the highest position in the wiki. I've put the wiki in the correct order again, removing the German entry since it was a label and not an artist (if I'm incorrect then put them back in the charts as either the 3rd or 4th artist). Please do NOT edit the order in the wiki again until the Austrian ZYX become more popular than the Japanese ZYX.