Overloading templates with same parameter list

[Joe]

I was reading over the Tuples article 
(http://www.digitalmars.com/d/tuple.html) and was curious about the 
section at the end "Putting It All Together".  What is the reason for 
not being able to overload on templates with the same parameter list in 
the case of a further parameter list being provided as in the example? 
Is it a technical limitation, or something that makes sense in the 
context of the language?

I would imagine the compiler could recognize the differences between the 
two delegates parameter lists.  Hopefully this specific example will be 
fixed once functions and delegates merge into one (as is mentioned on 
the function page of the language spec), but what about other cases?

As an aside, I truly am asking because I don't understand.  I'm one of 
the lurkers in the NG group that does his own thing with D (simplistic 
stuff I might add) and tries to keep up and understand what is being 
discussed here and is otherwise completely fascinated by the language. 
Reading through the spec however, that section caught my eye as it 
seemed like maybe that limitation doesn't need to be there?

Hopefully, I wasn't talking out of my arse with my questions.

Thanks in advance.

Joe