When using the virtual spectator slots in multiplayer (with a dedicated server), then the entity list is empty.
This is what I see when running the mission locally (Multiplayer but Player is server):
{F174594}
This is what I see in Multiplayer:
{F174596}
The entity list seems to be missing any (playable) AI units.
When a player joins, that player shows up in the list but the AI does not.