Vne is seldom set by stall or compressibility, it is usually set by the maximum qualified speed that the manufacturer tests to, based on where he stopped the testing. If the maximum level flight speed as limited by engine power is 150 knots, there is little to gain by making Vne 210 knots in a dive, so most test organizations simply cut off the speed where it is convenient to test, perhaps 10 to 15 knots above Vh.
Limits are interesting things, most limits are not set where the item turns to mush or breaks apart. Most limits are set where the tests were done, because the qualification is based on test, and cannot go beyond what was tested. In effect, the Vne is usually just the maximum tested, and represents a reasonable margin above where the aircraft cruises at max power.
Vne is sometime set where the handling gets poor, or where the margin to withstand an engine failure is minimal.