Since these types both have an "inferior" fourth thinking function, does this mean they're pretty strong in thinking? Since this fourth function is the motivation of each type, I would think the respective types would use them often.
For example, I have met a couple of ENFJs that have a stronger thinking faculty than their INFJ counterparts who have it as a tertiary function. Their affinity for thinking can be seen when they go into business which uses more quant skills than qualitative skills. I would guess that this dual T/F is due to an easier transition from a judging function to a judging function.
I would assume this would work on perceivers who have primary functions in N/S.
This is a hypothesis and a idea in development