I also would add, as you are trying to analyze the idea and examine if every shot fits into the framework.....in the first shot you assessed, of ML, to me, it looks like he is a little out of position in that shot and using his vast skills while out of position to create a shot despite his feet not being set for it.
In the second shot (is the third photo just earlier part of second photo? that is what it looks like to me)....in those two photos....to me it looks like your drawing of the triangle is unfortunately a 2 dimensional image laid over a photo of something that was originally three dimensional. So, where you are drawing the triangle and where it actually is on the person as he is making the shot may not be the same place.
But NextLevel's last line seems to address the issue in a way you may understand. Are you making your contact too late, too early, or in a range that is basically close enough to optimal. If you contact too early, too out in front of you, you will miss some of the power that your stroke can transfer to the ball. If you contact too late, you will also lose some of the potential power from your stroke. I think in those videos of you, you were contacting the ball a little on the late side. If you contact a little earlier in the ball's flight path, which will mean your racket has gone a little farther in it's stroke, you will naturally add more power to the ball from the stroke without the need of adding more effort.
So, it is about efficiency. A way of thinking about this, if you took your backswing, and then started the stroke, and I put my hand in the way of your arm to stop your stroke, near the beginning of the stroke, you would have a hard time moving my arm because your arm is in a position where it does not have much mechanical advantage. If I did the same thing near the end of your stroke, your arm also would not have much power to push my hand. But there is a point where your arm is part way through the stroke where it would be much harder for my hand grabbing your arm, would have a much harder time stopping the forward momentum of your arm. That is also where you want your arm to be, IDEALLY, when you contact the ball.
THEREFORE, if when you are practicing, you are making contact near that zone where you will transfer the most power into the ball, then, WEN YOU ARE IN A MATCH SITUATION like from the photos you posted, and you are doing whatever you need to to get to the ball and get the ball on the table, more often than not, the good training you did when you were taking the ball while it was in your power zone, will make it so enough of your shots, while your opponent is putting stress on you to make a bad shot, will still end up with the result that you are taking the ball while it is IN YOUR POWER ZONE.
In your photo #2, even though it looks like the player has taken quite a large lunge step to get near the ball, when he contacts the ball, it looks like the contact is somewhere in that power zone where it is a little out in front of him rather than the ball getting too far back.