Ranged AD spellcasters

Lately, we were struggling to find a keystone rune that fits Ranged AD spellcasters, such as MF, Jhin, Ezreal, Urgot, and Quinn. So why don't you just develop a keystone that combine casting their damage abilities and auto attacking to shred armor and/or to proc a crit damage. for instance, whenever a champion damage an enemy champion using damage abilities, that ability keep a mark on the enemy that can be proc using an aa. if that proc, the later damage can crit or even shred some of the enemy armor/mr. this kind of keystone shall let those champ to stop building lethality items and focus on creating new builds. what do you guys think?