How do 2 poison arrow clouds work?

I understand that the clouds do not stack, but what would happen if I shot a level 10 poison arrow, and then a level 4 into a spot? Which cloud would be the one dealing damage there? Will the 4th level override the 10th, or just be ignored?

I would assume it is coded to go with which ever is causing the most damage. Why would you ever do this?

I've had fun with pa with gmp and lmp, can crash your computer quickly.

Focusing mainly on poison damage. I want to start out with a nice high level PA attached to a Concentrated AoE, then while the cloud goes, stick with a level 1 PA attached to things like LMP, Added Chaos, and Reduced Mana. All those multipliers on the cheapest cost possible version of PA.

concentrated effect doesn't buff PA damage.

lvl 1 PA with added chaos and reduced mana and LMP will have really low damage, better off with split arrow in place of PA there. or some other aoe. Or just use high lvl PA with lmp and increased aoe or duration or something else. And then low lvl PA for single target damage, linked to added chaos and faster attacks or something else that buffs its damage. or use frenzy or ele hit.

I mean you can try it out, see how long you can make it work. Why not instead of reduced mana, you put mana leech on whatever you are going to spam, or use blood magic on life leech. I know the poison cloud damage you can't leech from, but my preference is just making a way to get your mana back, otherwise you will be spamming potions or running clarity aura even with reduced mana cost.