I don't use Mac, so I can't speak yo how the changes you made will affect your system. For future reference however, you should know that binaries are searched

I don't use Mac, so I can't speak yo how the changes you made will affect your system. For future reference however, you should know that binaries are searched on your $PATH in order. Instead of deleting anything, you could have edited your $PATH variable so that the directory that brew stores binaries in is searched before other locations.