Rules: Reverse all of Chia's trades while redrafting 2015 picks from reversed trades with ability to select any players below the draft position.
Here's the way I would've used Edmonton's 2015 picks that Chia traded, with the benefit of hindsight: Kyle Connor (16), Sebastian Aho (33), Mackenzie Blackwood (41), Anthony Cirelli (62), and Sami Niku (184). Add that to Connor McDavid (1), Caleb Jones (117), Ethan Bear (124), and John Marino (154) and one of Paigin (209) or Svoboda (208). Caleb Jones was selected with a pick acquired from TO but Oilers gave up an earlier pick in that round to acquire Gryba so Jones still lands in Edmonton if you reverse the trade.
I have not retained any player Chia acquired by trade. I have kept his Koskinen and Benning signings to fill gaps. I've also resigned some players whose contracts have expired in previous seasons (or just this summer) and as a result, I've gone over the cap. I've done this though to show the kind of talent Edmonton could've had if Chiarelli had made no trades.
Oilers would've been in salary trouble for the first time only at the end of Aho's ELC, before that they would've been able to keep this roster: Hall, making $6m, Cirelli on his $728K ELC, and Aho on his $925K ELC. With the need to re-up Aho last season, Oilers probably don't sign Koskinen to 4x$4.5m extension and look to trade one of the many elite forwards for the first time.
Before last season's arrival of Yamamoto, Bear, Jones, and Blackwood, Oilers would've obviously had to rely on other players. JP wouldn't have been rushed to the NHL, probably staying for a couple years in Finland before coming to the AHL and maybe entering the lineup for the first time last or this season. Chia brought in players like Maroon, Kassian, Sekera, Russell, and Nilsson as depth players. Russell is a definite no-go in my books but the others are/were decent depth players who would've been capable enough to get us here. Other options existed in our system though to get the job done. Brossoit was acquired before Chia. Fayne, Davidson, and Oesterle were defensemen in Edmonton before Chia and depth forwards like Slepyshev, Hendricks, and Pitlick, none of which Chia acquired, could've played roles in the absence of Chia's pickups. In fact, I've assumed in my AGM that Pitlick and Slepyshev have stayed with the organization rather than signing elsewhere.
All in all, the legacy of Chiarelli's era is just a source of great anger and trauma.