My DM uses this a lot in our text base campaigns where there might be a few key figure heads and the rest of the crew are one mass of fighters throwing their weight against you and it works fantastically, even if all on same initiative. Having a massive amount of blows coming at you all at on♓ce can be staggering, but taking on an entire crew all tactically seeking their targets would be. For finally bosses int the same way he keeps the hit points separate and rolls randomly to know which one gets hit, it allows for the boss to be whittled down just like your party and makes you feel the impact of yo𝓀ur fighting through the slug fest.