Load Multiple Signed Assemblies

I am trying to load multiple strongly named assemblies into the same database which are signed with the same .snk file (signed in Visual Studio).  I use the following code to create an asymmetric key and login as Books Online recommends:

CREATE ASYMMETRIC KEY SQLCLRKey FROM FILE = 'D:dbainAssembly.dll'

CREATE LOGIN CLRAssembler FROM ASYMMETRIC KEY SQLCLRKey

 GRANT UNSAFE ASSEMBLY TO CLRAssembler

GRANT EXTERNAL ACCESS ASSEMBLY TO CLRAssembler

REVOKE CONNECT SQL FROM CLRAssembler

Do I need to create a new login and asymmetric key for each assembly I load?  If so, do I need to sign each with a different key because its giving me an error message when I try to create 2 separate asymmetric keys/logins from 2 different assemblies which have been signed with the same .snk file.

The only way I've gotten everything to load properly is to create a separate key for each assembly and sign each, then create separate logins and asymmetric keys in the database.

Is this the only way to do this?  Or am I missing something?