Complex sentence: The reconnaissance was a conspicuous success so Shipton was again appointed leader for 1936 but in 1935 Tilman had not acclimatised well to altitude so he was dropped from the 1936 team, with his agreement.
Split into simpler sentences: The reconnaissance was a conspicuous success so Shipton was again appointed leader for 1936. However in 1935 Tilman had not acclimatised well to altitude over so he was dropped from the 1936 team, with his agreement.