It doesn't matter where around the earth you enter the VAB the only thing that varies is the incident inclination.
Are you aware that inclination is one orbital parameter that defines the orbital plane. If the spacecraft enters that plane at a higher speed, you map out an ellipse with a completely different eccentricity. The path is different through the van Allen belts.
The radiation in the VABs depends on radius, azimuth and polar angle, so does the ellipse on the orbital plane. It follows that the exposure of Apollo and Orion are different.
Luke, I have shown you that the only relevant factor is the inclination of the plane of orbit. Because the distribution of radiation is uniform around the circumference of the earth then it matters not the azimuth of entry. Why is this so difficult to understand? Speed is only important because of the component of time. The less time you spend in each zone then the less the dose received.The larger the elliptical orbit the greater the time spent in each zone. A straight line shot would result in the least time in each zone. Can't you see that?
No. Eccentricity matters.
And eccentricity is intimately tied to velocity.
Grab a copy of KSP and play around a little. Orbital mechanics are non-intuitive. Heck, I haven't make safe landing on the Mún yet! But getting your feet wet with a simulator helps.
It matters in that it moves the transit from a straight line to a curved line and thereby increasing the time to transit across a zone. it does not matter in respect to the zone that is encountered as only inclination determines that.
You don't move from a straight line. There are no straight lines.
Okay, I'm going to join everyone else here in trying out an analogy. Imagine a hula hoop and a basketball. Hold them up some distance from you (so perspective is unimportant) and aligned. If you turn the hula hoop so it is almost edge-on then that section of the ring can be hidden behind the ball. Turn it so the opening faces you and it doesn't visually touch the ball.
So far, we are in agreement. Well, here is where the analogy is tougher. Squish the hula hoop, bringing two sides together. Now it can share the same PLANE it was on, but be hidden behind the ball again. The shape matters, not just the plane.