I have a thought for improving Ashe's passive: every X auto attacks, you critically hit. IMO I think that'd reward her for actively trading and attacking more so than the current passive.
Is it a bit like Yi's? Yes, but I don't think it'd be broken if X were the right number. Maybe it'd get lower as she levels.
Its great and all.
It sounds a lot like headshot, but better in late game to land a 1k crit.
I like it.
I think Ashe need a passive like +10% critical chance.
Kind of stepping on 
's toes more than Yi's unless it's X consecutive attacks. TBH, I think Ashe's current passive really works for her as a character because it incentivises holding back until the right moment to attack, a central theme of the Avarosan and, to a similar extent, the Frostguard as referenced in 
's passive.
Now using Liss as a reference does give us a good idea for improving Focus: Bonus stacks whenever you impair a champion's movement with an ability. Currently, Ashe is the only Freljord leader whose passive isn't augmented by abilities: Liss's passive CD is reduced by 1 second whenever she impairs a champ's movement and Sejuani's passive activates on spells as well as autos to grant bonus Armor and decrease incoming slows. I do wonder, however, if a change like this would run counter to what made it fit her character in the first place (Volleys, Volleys everywhere).
That would be a lot better than what she has now. You could take it a step further and have other ways of reaching X. For example, every arrow that hits from Volley could count as an auto attack toward X to help give her some room for more plays and differentiate her from other passives.
I think they should investigate switching her passives. Move some form of her current passive or rework of it to her E (make it scale by the level of her E) and take her E passive and make it into her main passive. Of course it would have to be made more intricate than simply having flat 3 gold. But it seems more logical than how they have her current two passives setup. If she had the passive you suggested on her E, the number needed to reach X could be lowered by each level of E.
The problem of Ahse's passive is that to charge it you don't have to auto-atack.
All ADC are 75% of the time AUTO-ATACKING.
Riot should change that.
