You have a very good point.
As for "internal or external" term, those are just one type of catagorization instead of a belief, they do refer to a certain characteristics.
What is the content or the component one practice is the facts which one needs to face.
As we can see, based on Ibuki, Nogeri, sanchin, tenson....
In the Kyokushin case, Kyokushin is practice more "internal " components then most WCK which claim to be "internal'. it is a fact. IE some WCner claim SLT/SNT but did they practice thier SLT/SNT based on an "Internal" principle or practice such as the Kyokushin applied Ibuki in the Tenso and daily life practice? That is a question one needs to face.