Except for Kalev and Yehoshua, everyone over age 20 was destined to die within the 40 years wandering in the desert.
Was there any criteria used as to how many more years a specific person was to live within those 40 years?
Rashi to 14:33 says:
לא מת אחד מהם פחות מבן שישים, לכך נגזר ארבעים, כדי שיהיו אותם של בני עשרים מגיעין לכלל ששים.
Not one of them died before the age of sixty. This is why forty [years] was decreed, so that those who were twenty years old would reach the age of sixty.
Each person died at age 60.