What? Was he trying to hit the same spot while mounted, but not compensating for his height difference? The two emboldened ones should be exactly the same. Not sure these numbers are credible anymore, even if they do seem correct.
From what I recall, he explained that the ranged bonus mounted with polearms is the same as the ranged bonus from being a hoplite. When you bold 1h, you mean that 1h should also be +30? Not sure how he did mounted tests since they're not in the video, but can't you just use your own estimates for the effective range given the angle at which you need to lance and the distance/degrees of freedom you are allowed to move the horse's head?
Even so, it's not like you can really get a clean hit if you hit at the maximum range of the 1h stab. I don't think these numbers are perfect, but I think they are close within only a few points difference from my own experience. I've used right swings reliably against stabs with assumptions from this data and it seemed correct.