To clear Encrypting your wallet or file in which you store something only secures it from been physically accessed but when a internal attack like malware comes in then they would get access to it even with the encryption on it.

You don’t need the fourth location just follow the instructions above by Charles-Tim and make sure it is a three different location although the third location can be far from you since you don’t really need the third key to sign your transactions since it is a 2-3 multi sig. storing them in numerous places get it affected in terms of redundancy.