How to deal with Versioning my VSIX(VSPackage) that embeds two other VSIXs(MEF) as its dependencies?

How do we deal with the versioning of the extension (VSPackage VSIX) which embeds two other VSIXs (MEF). Some of these scenarios are confusing me:

1. What if I change my embedded VSIX extension (Version number still the same) and then create the main extension
2. What if I change my embedded VSIX extension (Version number changed) and then create the main extension
3. What if I do not change my embedded VSIX extension (Version number changed) and then create the main extension

Is there any internal mechanism to verify the version numbers of the dependencies with that of the main extension. 

My implementation will require random updates of any of the extensions, may it be the main extension or the embedded one.