For most of my teams I use that order (AoE, HP Steal, Single Target, Multi-Hit (like triple drill or double thrust)), but I keep Canola in front because she's my hardest hitter with over 6k ATK and I want to make sure all of her damage gets used. If my AoE users don't use their skills and use single hit attacks, it sometimes results in damage being wasted if Canola needs to finish off a weakened enemy. If she's first, she always gets a full damage hit in, and then either the AoE goes off and everything dies anyway, or it doesn't go off and they use their weaker attacks to finish people off. Example of something I kept seeing which is why I switched:
Basically, it helps in the cases where the AoE doesn't trigger, and if the AoE does trigger everything is usually dying anyway. For my other teams none of the units are that much stronger than the other so I just use a normal order since there's less of an overkill problem.
I'd probably put Marigold last in that squad, since triple drill can hit different enemies and can finish off a weakened enemy and then do damage to another one (less wasted damage).
OK, I understand your point of view.
I like to use AoE and Marigold Skill first to kill the low-HP enemies before my single target strikers hit the other(s). Most of the time my battles last ~3 rounds, I am sure I would use a different order if they would last less or more. Hard to say which order is better, in fact what I have learned for the past weeks of play is that RNG rules the Maps as well as the Battles, so I/we should not bother my/our-self too much with that. But I liked your input, so I will try different orders.
Yeah at the end of the day, unit order either doesn't really matter or is just playing the odds. I guess I should add that most of the way I have things set up is for farming 12-5, where there are those nodes with the small pest (sometimes pierce-weak) along with the slice-weak boss. I kept getting into situations similar to my example, so I switched and found it worked better for me.