As I posted in the Pens forum, McDavid has unreal speed, Crosby has unreal hands. While speed will fade over time, hand-eye coordination takes a bit longer. I think Crosby will be a more effective player at 37 than McDavid will at 37.
if we compare peak McDavid with peak Crosby, it’s so close. Obviously post-season success favors Crosby, and it’s hard to rack up assist numbers playing with some second-tier wingers for his entire career, so the stats favor McDavid but not as much as the pure numbers would suggest. Injuries also favor McDavid as Crosby has so many “what if” seasons after his first Cup.
Whoever you give the edge to is irrelevant, there is just not enough evidence to list McDavid a “tier” above Crosby at this stage in their careers.
Lets look at Crosby's and McDavid's most common all situation teammates for the periods between the 3rd and 5th years:
Crosby 2007-2008 to 2009-2010
Top 4:
Malkin 1936 minutes (59.11%)
Gonchar 1455 minutes (44.4%)
Letang 1386 minutes (42.3%)
Guerin 1182 minutes. (36.1%)
The next 6 forwards
Dupuis 883 minutes(27.0%)
Kunitz 777 minutes (23.7)
Sykora 612 minutes (18.7%)
Satan 479 minutes (14.6%)
Fedotenko 476 minutes (14.5%)
Malone 431 minutes (13.25)
Out of 3275 minutes in total
McDavid 2017-18 to 20
Top 4:
Draisaitl 2823 minutes (58.2%)
Nurse 2044 minutes (42.1%)
Klefbom 1833 minutes (37.7%)
Larsson 1316 (27.1%)
Next 6 forwards:
Nugent-Hopkins 1274 minutes (26.3%)
Kassian 1190 minutes (24.5%)
Lucic 740 minutes (15.2%)
Chiasson 673 minutes (13.9%)
Maroon 572 minutes (11.8%)
Rattie 450 minutes (9.3%)
Out of 4853 minutes