It's not as simplistic as about numbers, it's about knowing each other's games and strengths...being on the same wavelength.
For me, Klinsmann and Sheringham for the short time we had them was sublime, Teddy was a special player. Both had excellent football brains and experience and worked their socks off for eachother. They shade it from Berba and Keane who were a decent partnership, but not as good players consistently IMO.
Kane and Son have never really been a partnership in the truest sense of the word as the game has changed and aren't even really that well suited to play in a front two together in that sense IMHO. Hypothetical Kane and Klinsmann? Now you're talking.
It says a lot that I put Harry in front of Teddy now without much hesitation. What a player.