Traffic, the math isn't so wonky. The airspeeds in the checklist are IAS; at FL 320 an IAS of 200 knots would mean TAS of 340 at standard temp. Maintaining a constant IAS of 200 during the descent, the TAS would be 300 at FL250, 262 at FL200, and so on. Making 100 miles in 20 minutes is not much of a stretch- the tough part is not covering the distance, it's making the approach. Can't imagine what it must be like when most of the systems have gone bye-bye.