maxlib sort of does this since ages. In fact it uses 'maxlib_' as a prefix, so to make sure you get the maxlib scale and not GEM's scale use 'maxlib_scale'. This is not really the feature you suggest but has the same effect and can be implemented without having to modify any single line of Pd code.
imo, it's not very useful to have these nameclashes ... but for some important externals it would be worth to consider taking one of them to the pd core objects ... right now, i'm not using any counter, because of the differences between the different counter ... and since both maxlib and cyclone have objects, that do nearly the same and have similar names (e.g. borax vs. Borax) it would probably make sense to figure out, what the external _should_ to and cobine the objects of both libraries ...
implementing a (selectable) namespace for externals was one of the things that was discussed at the lad2conf in may ... well, but combining the efforts to improve pd is another topic ...
good night ... t