You do have a point. I have seen many familiar elements in many games. It's just a matter of putting your own spin on it to make it your own instead simply taking the idea and using it without really understanding how and why it works.
I used to use Photoshop, but not lately. I mainly use Procreate (for hobby art) and Pixaki (for pixel and game art).
Seriously though, your montage looks like a pretty cool crossover between my game and Mark's. It's actually pretty neat thinking about how my work or anyone's could interact with someone else's. Of course, we do have Super Smash Bros. as a shining example.