Based on the Mod, Component, & File Load Order as of Winter Patch thread, default load order used to be timestamp order when creating a game, and mod-id order when loading a saved game. It looks like timestamp order is now the default for creating and loading games. However, when the Leader Pack: Nubia mod is enabled, one of the configuration passes reverts to the old order during a saved-game load. That config pass also seems to drop all mods with AffectsSavedGames=0. I'm not sure yet what is causing that legacy/glitchy behavior for that one mod.