If you’re just asking if you can scale down the talking heads and place them in front of the opening video then yes you can, you could also add movement of these clips as well very easily.
Just place your clip on the timeline and select it.
Then click the “effects” Tab (next to the source monior tab) and click “Motion”. That will give you a Scale option as well as Position and Opacity options.
Scale the Talking Head video to what you’d like and you can even Keyframe the position to move where ever you’d like.
Now if you’re meaning something completely different like just masking out a floating head or something then let me know, I’m still not quite sure what you mean by “floating”.
Let me know;)