There's no way to tell this.
Not only are no two compiled DLL's the same because of the MVID and other properties that differ each time you compile: two assemblies containing the same number of methods doesn't tell anything:
- The implementation of the methods can differ (e.g. v1's
Foo()
method containsreturn true
, while v2'sFoo()
containsreturn false
) - Different source code can yield the same IL.
It seems like you have an entirely different problem you want to solve, like educating your team and using continuous integration to share assemblies that are compiled on a build server. If you can explain why you want to make sure two DLLs were compiled from the same source, perhaps some better answers can be given.