I decided to select 2 quests and two pulses, because I can see there one big benefit - if both mobs share same location, if it would be just one quest, it will kill all mobs in the are until whole quest is complete. So it might kill a lot of mobs.
When I did split into 2 quests and each quest contains only one type of mobs, then it will kill those and after that it will no longer kill them(unless there will be body pull), and it will move to 2nd part of quest and kill other mobs for 2nd objective.
But anyway thank you for your ideas, I think your approach is also very valid and it really depends on circumstances(are mobs hostile or neutral, placement of mobs, ...) what approach is better. I'm pretty sure I will use your approach on other quests.