Letang was a 3rd round fluke pick and Letang was not really a big factor until the 08-09 season, which is Crosby's 4th year by which time the Pens had already been to a Stanley Cup final and were well established as an NHL powerhouse.
IF the Oilers hadn't been morons, they very easily were gifted the opportunity to have a core of this
McDavid, Draisaitl, Hall, RNH, Barzal or Connor, Sergachev, Klefbom, Nurse.
In all honesty, I take that over the Penguins core group, yes even with Malkin.
Hall + Draisaitl = Malkin, RNH/Barzal/Nurse/Klefbom I take over Staal/Whitney/Fleury.