3 tests and 7 ODIs definitely looks too much but no more when you see they are to played over the period of 3 months. Not sure whether the one off T20I between India and South Africa back in 2012 was a tribute to Kallis as his homeground is Newlands, Capetown and not New Wanderers, Johannesburg but my point here is why would not want Sachin to play against South Africa and then schedule a home series for him after NZ series in the month of March (no IPL too in that month I guess) rather than forcing him to retire by messing up with the schedule? Mind you it is not confirmed he
will retire. Sachin fan or not, you would not like such a great sportsmen to retire against a weaker team. Instead, you or definitely myself would love to see him taking on the likes of Mornes and Steyns on their grounds like a gritty cricketer should be and then retire in the home series (scheduled at last minute of course) on a high. If he retires after WI series, there would be this feeling that he was made to escape (might be not the apt word) from his biggest test of fitness and technique at his age. Some people might even argue that he extended his career for reaching the milestone of playing 200 test matches. A series after South Africa series would have been fitting platform for Sachin to bid adieu and that would not have disturbed the schedule much.
Meanwhile,
WI confirms the tour. Fixtures are still to be announced. At least on cricinfo.