I have noticed this over several runs, but I think there may be some kind of pattern for which mobs will drop more of a certain kind of cell on the first floor.
Basically there are four wings to Arrapago floor 1. Two wings have bones, and two qutrubs. Two have one set of Lamia based on cell drops, the other two have a different set. I believe that one wing of the bones, and one wing of the qutrubs will have a better drop rate, as will one set of Lamia per cell drop set have a better drop rate.
I have noticed this pattern after many different runs were we will get either a ton of HP from the bones, or a ton of Weapons from the Qutrubs, sometimes both, sometimes neither, but the point was that its either almost all or almost nothing. Normally our pattern goes, clear the initial Qutrub/Lamia wing for weapons and magic, then depending on the group move to the other magic wing or move to the Bones/Lamia wing for HP and JA. We had almost everyone with HP and JA cells last night, and got almost no magic or weapons. This is just one night, but it matches many others. Sometimes lots of magic, or HP, or Weapons or JA, we just need to find the pattern.
Has anyone else noticed this? As there are patterns to the other first floor drops, I was thinking it would not be outside the realm of possibility for this to happen. I have noticed this with or without TH2+ on different runs, so I am pretty sure it is more than just that.