I have mixed feeling about this. The OP did a good job at portraying a situation where this works poorly, however if we want to do it justice - there are a lot of fights where you'd get screwed for pursuing that strategy. A big beast is not always a tough enemy. A sole enemy is not always cheesable. Try this strategy against spectator and you are doomed. Try this against bullete and you are doomed. I bet it might work with grym, not sure though. There are not even that many fights like that, where you are against a single powerful enemy. So we can agree that using help to bring back allies to 1 hp is as you say 'stupid' in this particular scenario. But is it stupid in general? Is it stupid in a githyanki fight? Is it stupid in a duergar fight in the underdark? Is it stupid in the gnoll fight? I doubt it. May be we should address the enemy and its behavior rather than the whole mechanic that works fine everywhere else