I feel as though replacing armor pen with lethality was a complicated solution to a simple problem
Correct me if I'm wrong but I don't think any of the issues with armor pen existed until Duskblade was put in the game. Aside from the Korean Lucian build, armor pen builds on marksman weren't all that common until Duskblade was introduced. So instead of replacing flat armor pen with a (in my opinion) inferior stat like lethality, couldn't we have just made Duskblade melee only?