Duplicating mobs/items.

Hello, what I wanna do seems very simple but I've never done this before. I just want to make a new mob, but have it behave exactly like pillagers just with a new texture. Keeping the random patrols and village raids as well. But I still want to keep the old ones. I also want to change the crafting recipe for the bow/arrows and make them look/sound like a gun. Maybe make it so you don't have to click and hold as long. But I want it to replace the bow. I want it to be compatible with MCA village guards, which can ONLY use the default bow. Then add a second bow to the game with a normal crafting recipe. Any help would be much appreciated. Thank you.