It depends on what you are talking about exactly.

Does soybean production as a whole, in SA, is worse than beef production as a whole in SA?

Maybe.

Does soybean production for direct human consumption is worse than beef production for direct human consumption?

Not. Even. Close.

https://www.wri.org/insights/truth-about-low-emissions-beef

Basically you're average meat-eater is indirectly eating more soy than someone having scrambled tofu everyday