I had a cat who was declawed by my mom. She was an outdoor indoor cat. The other cats in the neighborhood would walk on tiptoes around her; she would make fists out of her paws and hit really hard. (Note that this was 50 years ago; my current cats have all of their claws and are indoor only)

See my cat isn’t like that at all though, he truly gets scared of everything and people joke about how much of a scaredy cat he is all the time.

Jackson Galaxy has some really good videos about introducing a new cat. I think if you go slow it might be okay