Ok this model just haunted me for the last 2 days... i finally found it!

You compiled the playermodelmodel as "npc/cdc_soldier_npc.mdl" and then renamed it to "player/cdc_soldier_player.mdl"
This can actually break the game ,because it still stores the original name and when it does it does not find your model, because you renamed it.
Could you cange this? Just compile it to the proper name :3

Also: You don't need multiple models for npc's NPC's should work just fine with playermodels.