The fact Metro Exodus is switching from Steam to the Epic Games launcher exclusively for the next year, 2 weeks before release, and after almost a year of it being promoted on steam and able to be preordered on steam, is absolutely fucking ridiculous.
I'd recommend getting an i7 tbh, overall Arma 3 is a more CPU intensive game. The better your CPU the better, but your graphics card does have an effect on the games performance. So getting a good graphics card will help to some extent, but it won't make the difference. But a much better CPU will.
While burning do death you're also suffocating as the fire eats up all the oxygen, and... ya know.. you're literally burning to death. Would much rather drown to death than be engulfed in flames, but that's just me.