Ashe actually has no steroid, Draven has two damage skills (+1 being his ult, so 3), Graves also has 3 (He is classified as a ranged ADC, even though he is very obviously a ranged AD Caster), Sivir also has 2 damaging skills and a steroid in her ultimate (kinda like zed). Kog maw has 4 damaging skills, Corki has 3, etc...
There are so many exceptions to you "at MAX 1 damage skill besides their ult". Zed's auto attack enhance is not an isolation criteria (that's Kha'Zix and it's on his Q), Zed's is an execute. Zed can stay in the fight as long as any of the other "melee Carries". He does as much auto damage as any of them.
You could ALSO argue that zed gets a passive "steroid" (25% Bonus AD on top of what he's bought) essentially giving him more AD at all times.
I am indifferent when it comes to hash's articles, but to call him wrong in this case would be incorrect, in fact, riot already agrees with this stance on melee carries, they are going to change the melee carries to be assassin-like.