Thank you for all your input, it seems the problem is relevant and from the answers victim doesnt seem to have much of leeway if found with cards in possession. What about secondary SOS pin, which when entered only dispatches a random amount between R50-R200 only, with "insufficient funds" message for any higher values. Can that be a deterrent?
If you look like a hobo then maybe they would accept that your bank account is pretty much empty, cut their losses and just bugger off. But that won't apply to most victims and they'll think you're being clever with them.
In situations like these, the pressure is so extreme and traumatic that you go into autopilot. They will ask you how many bank accounts you have and how much money you have in each of them, and under the threat of torture and death to yourself and your family, you will simply tell them the truth. It will be made abundantly clear that if they catch you lying, there are no second chances for you and that your family will pay the price for your lack of cooperation. These guys have usually had plenty of experience and know the strategies that achieve results.
I personally know 3 people who have experienced this ordeal, and in all three I couldn't imagine any strategy that they could have taken to achieve a better outcome. They were all cleaned out to almost zero. You get put in a position where any action other than total compliance introduces a material change to the risk of death.
So it probably makes zero difference what the heck you do ahead of time, because you'll be meticulously explaining your security protocols and how to disable them anyway if it happens to you.