I think of it this way:

SA questions give you an argument that is missing something in order for the conclusion to be true. MBT questions don't require you to find anything missing.

In SA questions, you need to find another statement that will make the argument follow logically so that the conclusion must be true. In MBT questions, the answer choice IS the statement that has to be true.

Not sure if this is the best way to encapsulate the answer, but that's what came to mind!

I have taken a very familiar course in college called "Logic" or Philosophy 120. It goes over a lot of what's mentioned here and even goes into proofs, truth functions, and more. It seems to be a well known way to translate sentences using formulaic approaches.