@Stormwind- Assuming it's what I think it is, then... both
Some races (I think most, if not all of the 6 core races, plus Bretonnia) had the crew of their war machines released in blisters by themselves- great for putting with trebuchets, mangonels, or bombards (the siege machines available to almost all races).
The crew models themselves are therefore fairly common, but the blisters with just the crew (2 sets of crew per blister) are rare.