I would agree - attempting to convince/change the mind any high Si person can be the equivalent to the amount of work/evidence required for a research paper that will be published in a prestigious journal.
Here is the story called "the time my ESTJ boss gave me the most ESTJ response":
ISFJ office manager was retiring. She'd worked for him at the prior workplace and he brought her over when he started his own business. Read: she was a valued employee who worked for him for almost 20 years. He wanted to reward that.
My instructions were to get her a watch, approx value $5-9k, and he wanted me to look into a Rolex. Problem I see off the bat: ISFJ would not want a gift like that. She was almost diametrically opposed to anything flashy or expensive (which was, of course, ESTJ boss's world view - they'll appreciate getting something fancy/valuable that they wouldn't/couldn't buy for themselves).
I brought up this issue as it was glaring to me but got the "nope, this is what we're doing." Realizing I'd presented a counterpoint without 1. an alternative plan 2. other options which included detailed reasoning as to why this other gift might be more suitable, I found a timepiece that met both the requirements of his flashiness/value and her aesthetic.
I once again presented him with "I have this timepiece on hold; HOW-EV-ER, I would like you to consider the following:" and proceeded to give him my reasoning, list options, etc.
I see him nodding. I know this nod: he is humoring me but I continue regardless, knowing this is completely ineffective.
After I complete my presentation of gift alternatives and why a timepiece would not be the preferred option, he pauses for a beat and says, "
get the timepiece. It's tradition."
I got the timepiece. She hated it. It caused an enormous issue/rift. He now has $8k+ store credit at a luxury shop. We do not speak of this incident.
That said, I don't know that I'd necessarily label xSTJ
stubborn. I think that's a tad hyperbolic - to me, it requires an element of arbitrariness. SJ just wants very solid reasoning to abandon what they already know to work. If it ain't broke, why fix it?! I would say that if your aim is to challenge their opinion, you'd better come correct, have a plan, have solid, relevant evidence, and be at peace with the possibility of rejection, despite your best efforts. It can be done if you do it right, taking care to reassure Si (which can be a little squeamish out of their comfort zone) and appeal to Te (which has no time for chaos or half-baked nonsense i.e. you're not giving them more to do).
As an INTJ, I would agree with
@Nashvols assessment of "they have their moments" (mmm hmm) but also with the idea that I tend to be receptive to new/different approaches and roll things around before deciding. That is, while I'm not always easy to sway, very few things are set in stone for me. Even if your idea is only that - a suggestion with nothing worked out - I am usually comfortable with the gist of an idea as long as your reasoning is solid. If anything, a step-by-step outline could be hit or miss with me, as you may trigger my "don't tell me what to do or how to do it" switch (unless your plan is in step with what I'm doing/would have done).
My approach for things is to generally understand the objective (and prioritizing things as "musts," "shoulds," "in a perfect world," etc. - basically determine what, if anything, is expendable or "the cherry on the sundae" but not necessary to the finished product), consider the assets I have, and see an approximate vision of the outcome I would like. This is where the INTJs contingency planning style of thinking comes into play. Everything in the middle can be worked out, switched up, fail (as long as it doesn't take me to a dead end or require backtracking), etc. as I go and I'm happy as long as things are moving towards to my end game. The process is pliable (hence, perhaps appearing undisciplined in comparison to ISTJ). I think INTJ is more comfortable with, "I guess try it and see what happens." If you were to ask me at the start of a new project how I plan to do it, there are definitely times where you might think I don't know what I'm doing.
I might even feel like I don't know what I'm doing! I bank on my cache of contingencies, my understanding of the big picture, my self-confidence, trusting my intelligence and skills, and knowing that I'm
almost always successful. I usually tell people when they give me a project, "tell me what you want, when you want it, and leave me alone. I'll let you know if I have questions."