NY is a good, tough team but doesn't pop out as impressive
Yeah, they are greater than the sum of the parts, it's a bit confusing even for those of us who watch them every game. One thing of course is that they are missing Julius Randle, who was playing the best ball of his life before getting hurt, and who made the East All-Star team this season.
But that aside, I think this offers a bit of insight. If you sort all the three player combos in the league, NY has the 3rd best 3 man offensive rating combo in the league:
Hartenstein/Brunson/McBride
(behind only Harden/George/Plumlee and Embiid/Batum/Melton)
And the 3rd best 3 man defensive rating combo in the league:
Hartenstein/Anuoby/Hart
(behind a Gobert-led trio for MIN and a HOU trio)
So take those five guys, throw in two scorers in DiVincenzo (3rd most 3s made in the league this year, way behind Curry and just 1 behind Luka in 2nd) and Bogdanovic plus Mitchell Robinson, and that's a fascinating eight man rotation. Could they use another stud scorer? Absolutely. Will they be major underdogs if they face the Celtics like every other team in the East? Absolutely. Are they really hard to beat with Anunoby in there? Absolutely, they are 21-3 with him now, 20-2 when both he and Brunson play.