Playing with a debugger/disassembler would get you what you want, however there might be easier methods. It has been a while since I played with the Lord of the Rings games on the GBA and they kind of merged in my head so I can not say here.
Relative search could net you something under certain scenarios but for most part it is a text finding method rather than a stats one.
As far as the GBA goes pokemon is joined by Golden Sun and not an awful lot else for standalone editors or great scope.
