Since they buffed the attack speed on Augmentation it is now possible for sparrow to run Eviscerator and reach 419 attack speed. (Max is 420)
Eviscerator
Stormbreaker
Skysplitter
Augmentation
Dust Devil
Tainted Rounds
If enemy team has too much frontline you could run Ashbringer instead of either tainted or Skysplitter. Situationally, make that call.
Note: You do lose attack speed cap if you switch Tainted for Ashbringer, but it doesn't really hurt you if you're making that choice for the right reason.
This build gets you to 419 attack speed with all your stims on. That is 1 attack speed point below cap.
You have to be very warry of your positioning but otherwise, this is braindead.
I've tested it on both Drongo and Murdock, but, it just isn't the same. You get way more value out of them running Mana build, traditional build, or a variation of either.
I also recommend finding a variation on this build in a more organized team comp scenario, maybe abusing the Marshall item, or Muriel buffs, or both. You could possibly pump out more DPS grabbing Imperator instead of Tainted Rounds.