While too many authors using the same obvious expies could be considered a worrying trend in terms of originality, it isn't an inherently bad thing. As a longer time passes, creators might be more and more likely to make bigger changes to the character, eventually growing it into a whole new Character Archetype trope on its own. In other cases, it's possible that the resulting characters are too different even for that: Talented writers can explore certain aspects of a character with an expy,
