There are always things that will look similar, especially when it comes to naming things, however you don't need to think about it too much.
Water Pokémon can also use the Water Gun and I once read a manga Tenjo Tengo where there also was a guy who could do exactly the same.
You also should also take their point of view into consideration. Take it like this if you would start comparing the names of attacks of American comics and cartoons, how many dragon, tiger, lion, fire, lightning etc. references would you find? A lot, still you aren't going to say "hey, that comes from that show". It's no different in Japanese, it's just their language. Agreed I doubt something like Chidori is common, however water shot or gun is really something basic.