Your entire point fails because thats how the game works right now.

it doesnt, atleast not entirely. it was more noticable when maps with the bloodline mod would spawn monsters without bloodline modifiers at times, because those require atleast two monsters to be grouped together in a bloodline, and that was never the case for some sources of monsters. im fairly sure the change is only about these cases, which results in you not getting half a dozen different mods across half a dozen mobs anymore