You missed what he was trying to say. Actually you completely missed it. He is not claiming that a certain missile has range more than the other missile, but rather what is the chance that a missile can hit a target SUCCESSFULLY within those range limits. A missile having a range of 100NM will not have a 100% kill probability at 100NM. It will be far less than that. There has been numerous discussions here and on other forums that the way missile range is calculated is very misleading. It is not standardized at all. Russians do it in a different way than Americans. A missile that is approaching head on to a target has a higher chance of kill than the missile that has to put up a chase. And if that chase is already 50nautical miles behind, then the missile has a low probability of kill.
The AIM54 Phoenix was a mammoth of a missile, with 100NM range, but was superseded by shorter range AIM120. So it is not exactly the range that matters. But the chances of kill. And beyond a certain limit, like speed, altitude, direction, turn rate etc, the dynamics of the missile govern the chance that if it will hit or miss the target.
The last part of your post stating Underdevelopment etc is not relevent here. Aim120 and SD10A are both in active service and more than enough that PAF needs.