8 minutes would be pushing it even with 160 kts to 4 miles. The point is that with radar there would have been no delay; used less fuel, with the passengers arriving sooner.
An experienced approach man will be able to improve on 1/10 to probably 1/6 if the timing is right to go outbound at holding altitude for a while.
Next question: where will they all park. You just need a easy to go tech again and space will be at a definite premium.