You mean like two clubs wearing navy blue and white in different designs?I think a guernsey/colours and brand is a huge part of a club's identity. My view is there needs to be some control and that an increase in similar colours + guernseys + designs weakens the identity and brand recognition of each the more similar they are. The actual clubs involved make no difference to me. I wouldn't want any current club identity to be weakened.
Or two clubs wearing red, blue and yellow in different designs?