I once won a game as Shaco by being annoying, not good.
I bought
and then just spent the entire game hitting up lanes and getting them to chase me.
I wasted so much of their time that my team pushed the lanes to a victory.
My team said I was trolling.
Why is this relevant? Because Shaco still is the same thing in essence. You can win without those items equally. If your issue is the 100-to-0, it's definitely not the only champ and coincidence is not a thing. Every single champion lately I've seen people complain about in recent days has been using Lethality in example after example. It might be a red herring of another composite issue.
(Duskblade causes vision issues, you can't always read a duskblade-killed ward in a second via the minimap.)
(Edge gives movespeed, which allows a quicker in.)
(Edge has a shield, causing irrational durability despite countering the surprise attack correctly.)
(Duskblade causes assassins to deal true damage on their first hit.)
(Assuming IE in your example, Edge and Duskblade give 125 AD, increasing to 195 AD with IE. It can Crit for +50% crit damage.)
Composite issues happen more frequently than people think. Mages are at a not-so-high point in my opinion. (Again why relevant?) I see a lot of micro-issues that composite into a larger issue that manifests in things such as mages being used as supports more recently.
So, with the above as a consideration:
What do you propose? Nerf Shaco? That's still not really fixing the issue, it's creating an issue for Shaco while the micro-issues remain.