After looking through the code and playing with a few things I have managed to get the enemies to have box collision shapes and also have the update from physics to game scene working fairly well.
I will definitely need to re-factor quite a bit of this code to get it to work in a way that would integrate a little easier with an Entity Component System. I have been thinking a little about my current design and have also made the code that was already there a little more flexible.
I think the next post will be mostly about the design that I am going to implement before I dive in and start coding. I don't want to make the same mistake as last time ;)
As another note the fact that Unity uses Physx and also an Entity Component System may make my life a little easier as I can see how they have done it and take some guidance from that.
Would be great to get this physics work integrated fully and in a flexible way soon.