This game when I'm in enemy fights the framerate struggles (this happens in the first quarter of the game and to be honest it doesn't annoy me but I'm curious I want to know is it from the game or is it from the system or something like that?)

You're referring to SP, I presume? I haven't had any noticeable framerate issues but it's not uncommon to have some slow-down when there's a lot going on on the screen at once.