My two cents on the subject: The working principle, both in those Longines examples and in the TH36RS, is the use of a vernier scale, which should be familiar to anyone with a little knowledge about machine shop measure instruments. Indeed, the 1/10 of second can be read where a mark in the moving scale, either attached to the seconds hand (Longines) or to a rotating bezel (TAG Heuer)) coincides with a mark in the fixed seconds scale. TH used to have a video in their website explaining the process, but I don´t know if it still can be found there.

This clever device visually "amplifies" the scale, in order to facilitate the readings, so I don´t think that the frecuency of the movement (VPH) is necessarily related with the accuracy of such 1/10 second reading.

The second picture in TZ-UK posting shows a limited edition Longines stopwatch called Honour and Glory. It was issued in the late nineties in a nice black lacquered wood presentation case, along with an ETA 7750 powered wrist chronograph styled along the same lines.