Take a look at this
"Closure rate 1000kts. In the air GS has no affect on closure rate."
That has to be one of the most stupid things i ever heard. So basically what you are saying is if my aircraft has a TAS of 500KTS but a groundspeed of 400KTS that it will have less of an impact then if my aircraft has a TAS of 400KTS but a groundspeed of 450KTS ??????????????