He played like a top 5 QB Week 1, but he most certainly did not in Week 2.
After 2 Weeks Dak is only top 5 in two meaningful QB stats.
Completions? 2nd
Competition %? 3rd
Yards? 7th
TDs? 15th
INT? Tied for 7th most thrown
TD%? 22nd
INT%? 13th
Y/A? 16th
Rating? 14th
QBR? 14th
So, that doesn't look top 5 to me through 2 Weeks. He looked great Week 1 and looked decent Week 2 and his rankings reflect just that. All this will improve as the year goes on, but Week 2 was not a great game no matter how you slice it, because after Week 1 Dak would have been at least top 10 in all this stuff, but that.
Again, it's just numbers. I believe Dak is easily a top 10 QB, but not top 5 yet, because he hasn't shown the week after week consistency.