While the Sherpa were crucial to success of the expedition, it's also important not to jump to the other extreme and underestimate the contributions of the British party. This was not a "guided" expedition where the clients were just going up in the wind shadow. Back in 1953, it's pretty unlikely that sherpa party could have summitted on their own.
If I remember correctly (it's a while since I read Hillary's account of the expedition), only three of the sherpa were able to go up to camp 4, and two of those them had to turn back due to altitude sickness. Tenzing Norgay did not have the technical knowledge to operate the oxygen systems. Also, crampons were far less advanced back then, so the mountaineers were also responsible for cutting steps every few days for all the routes that the porters were using to haul gear.
If I remember correctly (it's a while since I read Hillary's account of the expedition), only three of the sherpa were able to go up to camp 4, and two of those them had to turn back due to altitude sickness. Tenzing Norgay did not have the technical knowledge to operate the oxygen systems. Also, crampons were far less advanced back then, so the mountaineers were also responsible for cutting steps every few days for all the routes that the porters were using to haul gear.