I don’t think 380MB for a 3d game is a lot. That’s quite normal or even low these days, and it’s mostly because the game engine is quite advanced.
2GB on your device should be enough though, I ran JWA on 1.5GB a while without issues and even 1GB kinda works. I have 2G too now and never have a crash. I think your phone has other issues.
One thing I can tell you though, is that clearing RAM, and manually closing apps in order to “free up space” is the most pointless thing you can do with a phone. Just let the device run its own memory management. When it needs more, it will choose an app to close in the background. This is automated to a very sophisticated level and you shouldn’t bother trying to interfere with it.
You might just have too any apps on your device, or it’s old, or broken.