We'll be travelling to southern Africa this year for a trip I've wanted to do my entire life. The safari part of the vacation (half will be spent exploring the Western Cape) will take place at Tintswalo Lodge in the Manyeleti, South Africa and Mashatu, just across the border in Botswana. Both are private game reserves and at one of them, we'll have our own private vehicle. At the other, vehicles are limited to 6 people and we're 4 - so it'll be almost private.
For cameras, I currently own a 1Dx2 and plan to rent a 5d4 to use as a backup camera. My main debate comes to lenses. Due to weight restrictions, I can take only one big telephoto. For those who have been on safaris, which of the following options would be better?
a) 200-400/1.4x on 1Dx2. 70-200/2.8 II on 5d4.
b) 600/4 II on 1Dx2, 100-400 II on 5d4
Thank you for your help.