This may be useful, I'm not sure...
Aminet search: Tool aliasExcerpt from Tool Alias' readme:
"ToolAlias provides a mechanism for rerouting specific programs to other programs. For example, with ToolAlias, you could reroute all references to ':c/muchmore' to use instead 'sys:utilities/ppmore', so that when browsing documents on a Fish disk, you get to use your favourite text viewer, rather than loading the one specified in the document's ToolTypes."
It's a little old (1993!), but it's so small it's unlikely to be able to cause any problems, and it would save you from having to rename either more or the default tool of every readme file you have.
(Oh, if only deficon had been introduced earlier in the Amiga's life, this sort of stuff would be so much simpler! ) :-P