None of these attacks are touching.
Roger's attack manage to even go thourgh Oden's block defense.
You said that explosions are combination of ACoA and ACoC. All attacks I showed are doing it.
Here the moment they touch there is no black ring and Luffy heavily implies he is using barrier haki.
Then Oda just made this shit to represating the clash of their haki on the image you showed. Nothing like what you said.
Once again no black ring
Then suddenly he wants to represent like that again. No specific reason just artistic choice.
Finally no ring when Luffy beats Kaido