Funny thing, it's just the object model in play that causes the problem. Something more similar to Smalltalk (or Objective-C) works pretty well for things this

Funny thing, it's just the object model in play that causes the problem. Something more similar to Smalltalk (or Objective-C) works pretty well for things this dynamical, though you do need to factor out the properties and messages reasonably well still. The trouble is C++ and similar object models poor support for composition and implicitly penalizing uniform object structure. (E.g. call multiple base methods in a subclass - pain ensues. Add virtual calls to the mix, it gets really iffy.) Even Python and Ruby with explicit mixins but the old model get hairy.