MBTI and Socionics have different naming.
ISTJ in mbti is a “Judger” but their main information processing is actually a perciever function. This only applies to introverts, extraverts in MBTI are ENTJ = Judger etc
The thing is not to exclude the possibility of being LSI, since LSI and SLI share strengths, just different values. I would be interested in your conclusion after a bit of reading. Just ignore the physical aspects of these descriptions, just your subjective view on it. Socionists rely too much on visual aspects, and not cognitive. I would say you can pick and choose any type you want to be if you like, since these are different system, you shouldn’t be forced to conform to some abstract theory.
Outwardly seems business-oriented, somewhat severe, cold and unapproachable. A realist and skeptic, distrustful of novelty, and of those who advance ideas of declarative nature [slogans?]. Will always avoid working on useless projects due to pragmatic nature. Very dynamic and technologically effective. Can extract maximum benefits even from something that is seems useless. His products are always at the forefront and will stand up to any competition on the market. In clothing he is restrained, conservative, and prefers a sporty, technological style.
A person of this sociotype is easy to notice from distance by external characteristics. However, this mostly applies to male representatives, as women of this type typically don’t have any striking external features. The first thing that strikes the eye in figure of the LSI - is certain fundamentality, solidness. A person of this type solidly stands on his two feet, which gives an impression of solidity and firmness. His head sits on his shoulders straight, almost not turning. His body tends to turn together with his head. When walking, the LSI doesn’t swing his hands. His hands seem fixed at the elbow, his palms and fingers do not hang. Sometimes it seems that he’s holding his hands by his sides. LSI’s gait seems soft, smooth, gliding. However, at times he makes sharp turns and deviates from the previous straight path. The most notable feature of his face are the cheekbones. Due to this, in his facial appearance there is something eastern, Asian. The tip of the nose may be turned upward. The expression on his face is usually static, fixed, inexpressive and focused. Male representatives of this type may have beautiful, lush mustaches. LSI’s clothes show signs of tidiness and neatness. His dressing style is usually strict, inconspicuous, not wrinkled or dirty if possible. Men of this type always look good in military uniform. To violations in dress code, when someone comes to their post dressed inappropriately, they relate quite critically.
Sorry for wall of text. Since I am trying to just relay information, and not my opinion.
Some more I found…
SLI, ISTp (Sensory-Logical Introvert): EXPERT
Character : his strengths - the ability to make sensible and useful deeds. He loves tinkering and rarely asks for help to others. Inventor in the home and at work, which he likes. Mistrustful to new ideas, but if you check them in practice, is able to extract the maximum benefit from them. Very modest and undemonstrative, does not like to exhibit their achievements show. The soul is sensitive to compliments. Do not accept egalitarianism. Worry, if the results of his work is not appreciated. Opponent volitional pressure, prefers to financial incentives. Mandatory and punctual, but really depends on the mood. The fact that he considers right, stubborn and uncompromising. Proud and very independent, but appreciates friendship. Faithful in relationships, sensitive and attentive to people. Very impressionable, poorly control their emotions during the dispute, what then sorry. He does not like to show their feelings, especially in public. I inclined to skepticism, irony and loves to joke. Hidden and silent, kept in communication at a distance, not like familiarity, can put people in place. He appreciates comfort and convenience, she loves change experiences, willingly traveling.
LSI, ISTj (Logical-Sensory Introvert): INSPECTOR
Character : Loves around the accuracy and specificity. In cases and estimates sober realist, I do not like fantasy. Suspicious of new ideas in all required facts and evidence. Artists and assiduous detail is working on the details of any case, everything leads up to the end. To all cases prepared in advance, intolerant laxity and indiscipline. Respects the laws and regulations, works well with the documentation. Economy and rational. It has a developed sense of duty. Monitors the implementation of its orders, does not accept the objection that thinks is right. Very strong-willed, tough and hard-working people. The case raises above sentiment; people evaluate the results of their work, regardless of sympathy for him. Mild takes into account the individual qualities and abilities of people. It attaches great importance to financial incentives. Not flexible enough in a relationship. Poor understands the feelings and motives of others. The soul distrustful, closed and secretive. His silence is experiencing problems without turning to others for help and sympathy. It has an exceptional sense of responsibility for their families and peers, and becomes their support in difficult situations.