After some thought ....

Surely it's just a case of qualification. We all think of a henge as a bank with a ditch inside, regardless of size. So you have small, medium, large and extra-large henges. Some have pallisades around the rim. Some have timber circles. Some have stone circles, some have barrows.

So, you could have a medium pallisaded henge with internal stone circle. What's wrong with that? You don't need another name to describe something everyone* will understand if it's written out in full.

*you know what I mean