You should probably look at the CAAC standards. What NATS does is not the only standard. The FAA std is completely different. FAA req's min sep from threshold to 5nm, and with RECAT (Memphis so far) from threshold to 10nm.
Min radar sep is 3nm, and wake sep varies, and with RECAT, there is no visual sep allowed.
With regards to speeds, there is the CAT speed of the aircraft approach. CAT C is 140 kts for the final segment. You wont have aircraft like A380's at 160 kts on final either...
Not sure where you are located, but 160kts at Lhasa or Linzhi would be entertaining for everyone!