Well I would have no problem giving up Greg Nemisz (Calgary selected him with Montreals first round pick), Louis Leblanc, Jarred Tinordi and Nathan Beaulieu. Those were the 2008 - 2011 picks. 4 consecutive busts or nearly busts (Beaulieu). Even McCarron, Scherbak, Juulsen and Sergachev (the 2013-2016 picks) would be fine to give up for Draisaitl. So giving up 4 first rounders might not hurt that much.
On the flip side of that you have the Vanek offersheet, where the Sabres could have received 4 first rounders that would have ended up as:
2008, 12th overall: Tyler Myers
2009, 10th overall: Magnus Paajarvi-Svensson
2010, 1st overall: Taylor Hall
2011, 1st overall: Ryan Nugent-Hopkins
That would have been a massive mistake for the Oilers.