In the case of swarm queens, you'll note that the workers control who gets to fight and who doesn't.
The workers control which swarm cells get destroyed and which don't.
The workers affect emergence in severely crowded brood conditions, allowing afterswarms (which are a bet with a small cost and a big payout, and a queen elimination strategy). Among peer queens, those of similar lineage submit, older allowing themselves to be killed (look up the normal queen bee fighting research). If the genetic lines differ, the war is on.
Sick bees are not killed - when they fall to the floor they are dragged out, same as the dead bees. Sure would make things easier if they were. Old bees are not killed - they serve as the outer layer of the cluster, with abdomen temperatures at ambient, burning out their last supplies to keep the cluster warm.
The colony, in effect, operates as a single creature, whose cells happen to be capable of independence, but never doubt that it is the workers in control, and the most bitter battles are those fought to defend the entrance to the hive, because it is the gateway to the brood and the food.