Changing Nasus E from armor shred to armor penetration could help him

So basically, what I suggest is changing the 20/25/30/35/40 armor reduction of Nasus's E into armor penetration for him and his teammates. What does it change? At first sight nothing, but it affects greatly synergies with %pen items. Indeed, reduction applies before penetration and basically makes Nasus' E have an antisynergy with and the %pen mastery of offensive tree. And I believe that if the penetration of these items would go before the shred of E (so basically changing his E to armorpen instead of armorshred) would help him without actually doing any great buff. First off, we could see a new kind of juggernaught Nasus with (doesn't mean squishy, he would pick it up like other juggernaughts pick ) making his build look like : and his identity of a lifesteal based immobile juggernaught would be reinforced. We could even see Warlord's Nasus, more immobile than Stormraider's and slightly less tanky than Grasp but more lifesteal heavy and actually being a damage threat to tanky champions... basically the people he is supposed to face since he can't reach the backline due to the nature of his kit. It also slightly helps his utility in teamfights by making him have higher synergy with his ADC that has (upgraded or not).

Overall a really invisible buff that could actually do good things.