The ANC is not naive, just viciously and systemically corrupt. They know the institutions of South African statehood have been raped, depleted and looted by their own hands, it's just a matter of time before they lose any central authority from Pretoria, probably in the next 20 years or so.

Abandon all hope, ye who enter here.

In all seriousness, they're just taking the money, saying what Russia/China wants so long as it personally enriches them and will probably find themselves in quiet exile in 20 years. Probably in Singapore, and never having to face the consequences of their looting of an entire country's wealth and prosperity, and still not actually throwing in and living amongst the shithole states they claim to idolise.