I was sifting through WoL top SV parses earlier today on Iron Jugg, Thok, and Malkorok to see how their openers compare to mine. The parses that I pulled all show Crows being around the 5-7th cast.
Being as how Crows updates dynamically and has a 30s duration, wouldn't it be more likely to get the full benefit of trinket procs by casting it earlier? Usually both trinkets have already gone off by the 5-7th cast in the opener - at least for me. That means that by casting it late, you can easily lose decent chunks of the trinkets duration.
Looking at the AoC trinket, the duration is 20s. So even if it procs late in the opener, there is still a 10 second window where you won't lose any stack time by casting Crows early. Where as, more often than not (at least for me), it does proc early, and by casting Crows late, you are going to lose some stack time.
I might be missing something crucial, and I do realize that the differences are likely minor, but I figured it was something note worthy enough to bring up and get some feedback on.
EDIT: Also, due to the cooldown on Crows being 5 seconds longer than the trinket, by casting it later you are more likely to drive their alignment further apart later in the fight.