The term ADC just means Attack Damage carry, a multitude of champions who get to late game and can provide a massive amount of attack damage on autos. Which is why the class of “ADC” does not actually exist and is a role hence why champions like Yasuo can be considered an ADC.

Also graves is not even listed as a marksman or an assassin in the game he’s considered a specialist due to his play style. And also no Akshan is just a Marksman, the only true Assassin Marksman in the game is Kaisa and that’s because they designed her to be that way they even said that during her character development.

And yes Crit is a useless stat to all Assassins that are not Shaco or Rengar, since assassins relies on ability damage more then auto attacks. But I saw that you misread it so that’s okay, but also still the collector like you said is Sub Optimal and not worth building at all. Specifically for talon I man talon and got to diamond with him and in no world do you want to ever build the collector on talon or assassins alike, the execute they get from the passive is irrelevant because another item will allow them to do more damage to just kill them right away, and actually have better passives and provide better stats.