Hi Juju,
Actually, I wasn't really downing Socionics, and when I mentioned "subjective" it was towards the articles I tend to find about the types. Also, I believe that VI is legitimate. But I still have not seen articles demonstrating the practicality
outside of finding good personal relationships (which is what I meant by "matchmaking"). For example, I'm looking for something along these lines:
Suppose we are trying to decide which type is suitable for a certain position/rank in a team, where he/she will need to make a decision on his/her own based on the information provided. Now we are stepping outside regular type descriptions and focusing on informational processing. Let's consider, for instance, the reason why EII would not be very suitable for military leadership (non combat) position in general. Basically,

as leading function will not consider and naturally think of solutions that go outside their value system, without previous exposure to these at some point. However, due to their introverted nature, they would be more suitable in a position of military strategy, rather than actually directing the military actions to take. But, this would be true with Ijs in general, in terms of favoring plans and well-thought of actions, instead of quick ones. In terms of the kind of thinking they could provide, EII could focus on other aspects of warfare, such as moral, and they might do well in this regard.
What I wrote above might not be 100% true in general, but it's just a basic example of what I mean.