A long term consideration of the S Africa complex- that I’ve gained through experiences both good and bad- a British complex gives you the capacity to produce 10 pieces total. Given competent Axis play, Britain should not be collecting 30 IPCs for very long (sometimes never after the first round). So that means less than 10 Infantry per round. If you’re building anything other than Infantry in S Africa that also means you’re probably getting far less than 10 units- maybe 6 or 7 total.
If I’m the German player the initial 15 IPCs for the complex + the lessened pressure in the north makes me feel more at ease.
On the plus side it will make it more difficult for Japan to get their meathooks into Africa. If you keep your Indian ocean navy lingering in SZ 34 for a time and then move to S Africa with it it’s a potential thorn in Japan’s side.
I’ve definitely tried it and had it work against less experienced players, but even in those situations I could have probably used the IPCs more wisely.
I’m not trying to shoot down the idea, just pointing out the sacrifice that you have to make elsewhere on the game board.