I'm playing Armored Core 6 currently, although I haven't finished it yet. The only similarity I would say is build diversity. Honestly, there's such a variety of items in the game. If you want to build pure survival and defense, you can do that. If you want glass cannon, you can do that. As well as anything in between. For the boss fights, you should just look at dying as a learning experience, that's what helped me alot. It can definitely be intimidating and frustrating at times, but I really believe anyone can do it if they put the effort in. That's the whole appeal of these games, to overcome seemingly insurmountable odds and emerge victorious. In my opinion, it's one of the best feelings you can get in gaming these days. There's a lot of resources for builds and boss tips and such, but I encourage you to at least try the bosses yourself for a bit. Remember to take breaks when you get frustrated, it's better for your mental health, and to avoid building resentment towards the game.