Forward: I know it is an overused phrase to use for lame posters but it was just too apropos. Also I technically wrote most of this post 4 years ago when Yamada-kun and the Seven Witches anime was on TV but I decided to finish it since I JUST finished the 3rd season of the Rin-ne anime which inspired me to finally finish this.
Remember when Kyon from The Melancholy of Haruhi Suzumiya was a popular character? For a while he spawned he spawned about a dozen similar anime leads who were similar stoic with a bit of sarcastic edge to them. This is hardly a phenomenon solely centered around anime. Success tends to breed equal amounts of homage, inspiration, imitation, and plain and simple copying in media. I think it was just Kyon that made me mentally track trends like that in anime more than anything else I can easily remember.
Most of the time when people notice a trend like this it tends to inspire a good deal of cynicism. When you see a dozen characters all with a very similar character in a short period of time it does really make it seem like media has completely run out of ideas. Add on top of that the fact that the Johnny-come-latelys often never match up to the original only exacerbates that feeling of despair. I myself try to find similar characters who on the surface seem like they are doing the same thing but instead find a way to distinctly find their own niche. There is no real lessons to be learned from the first case that is not immediately obvious after you learn it the first time. The blind copying of a trend is just as easy to criticize as it is to do. The far more interesting examination is an analysis of the cases where similar characters are able to differentiate themselves or even fill different roles.
The characters who recently brought this to the forefront for me are Sakura Mamiya from Rin-ne and Urara Shiraishi from Yamada-kun and the Seven Witches. At first they seem remarkably similar. They are both young ladies who seem to be the only characters who constantly keep an almost robotic stiff upper lip despite the strange supernatural activity happening around them. They both act like straight-men for the rambunctious characters around them. They both also seem to be fairly unaware of the romantic interest that the male lead has for them.
It is really easy to assume that these characters are merely carbon copies of the other. A closer examination will show that they are actually very different when you examine them beyond the simple examination you would make in a snarky image post.
There is always one thing about Fate/Grand Order that has always slightly perplexed me. During the 
Reverse Thieves 
