After 5w4 I would say personally that 2w1 comes before 9w1 as I am widely considered a very helpful and kind person who can at times be overly helpful.
That would make your tritype 5w4 - 2w1 - 9w1 So/Sx/Sp.
I'm not sure if it's been said, but I imagine that since there are three types in the tritype and three instinctual variants that each type would take on an instinct accordingly. An example in this case: 5w4 So / 2w1 Sx / 9w1 Sp.
How do you feel about these descriptions?
"Sexual Twos feel that they will feel loved by attaining complete, profound intimacy with someone. Thus they are driven to be as close to their loved ones as possible. They attempt to win a place with people by focusing intensely on the other's needs, hopes, and interests. They enjoy the process of learning about potential partners and make it their business to become acquainted with the other's world. It is as if the Sexual Two was seeking to get "in synch" with the other in as many different ways as possible. Similarly, the Sexual Two will enjoy finding out what the other likes, whether it is a favorite food, cologne, style of music, or favorite place for vacationing. Needless to say, Sexual Twos will then do their best to provide these things for their intimates. Moreover, most people love to be the center of attention, and Sexual Twos know this, lavishing the other with attention, affection, and praise. In this sense, they are seductive-getting others interested in spending time with them by making the other their object of adoration. Sexual Twos also like to touch and be touched by the people they are drawn to, often initiating physical contact in a relationship—even in a friendship. When less balanced, Sexual Twos can become obsessed with a lover and can have great difficulty letting go of a relationship."
"Self-Preservation Nines are perhaps the most easygoing Nines, but they are also the most likely to need time alone, untroubled by other people's influence and requirements. They seek a sense of well-being through comfort: familiar routines, "comfort foods," and a supportive, uncomplicated environment are all highly valued. Self-Pres Nines have their own way of doing things, their own pace, and their own philosophy of life, and they will stubbornly resist any effort to change any of these things. Self-Pres Nines are also people of few words, preferring to communicate in nonverbal ways. They often pretend to be less savvy and aware than they actually are, as if tempting other people to underestimate them—so that they will be left alone. Positively, they are grounded and patient, possessing a great deal of common sense. They tend to have problems with overindulging themselves in food and drink, or conversely with rigorously controlling their diets—this is especially true of Self-Pres Nines with the One wing. They may also lack physical exercise. In any case, having their routine and lifestyle change is very challenging for them.