There's already a lot of good information that's been said. I've been out of touch all weekend so I am late to the party.
I will inject however, that there are some somewhat misunderstandings.
Crucible steels in history and even Wootz have varying chemistries, however, the concentration of these elements are very low, usually. We are talking in the trace ranges and some cases just a bit higher. So ~.005%-.1% by weight concentrations of carbide forming elements, such as Vanadium, Chromium, Niobium, Phosphorous, Tungsten, etc...
The funny thing about ore deposits, is that you can crush and send an ore sample from under your feet and take 5 paces in any direction in that ore deposit and take a sample and have pretty distinctly different concentrations of elements from ore sample to ore sample. I have done this in practice. My smelting partner and I have sent off dozens and dozens of samples of ore to be tested from various ore deposits in my country. We do this for our traditional smelting.
I've also never encountered an ore or even a piece of scrap metal that didn't have the minimum required concentration of elements to create carbide formers capable of being nodes to eventually create a watering pattern.
The carbide formers play an important role, but they do not really make up the pattern you see. They tell the cementite (iron carbide) where to go every time the steel is heated back up, but unlike "alloy banded" monosteels in modern steels, crucible steel's pattern is made up of extremely tiny spheroidized blobs of iron carbide with the foreign elements more or less are somewhat evenly scattered amongst the steel, and these exist amongst a sea of pearlite. They are where they are from the time of solidification, and my melting procedure ensures these to be as evenly dispersed as possible. The lamellar sheets of cementite in low alloy crucible steel can be seen below. Keep in mind this is a cross sectional view (like from the spine).
In alloy banded steels, the less pronounced swirly patterns are made up of large, irregular non-ferrous carbide with high concentrations of cementite gathered (cementite is attracted to non-ferrous carbide more, the larger the carbide is), while leaving zones of carbon depletion, forming ferrite. Below is an image I found of an alloy banded steels. I am not sure of the alloy, but alloy banding looks pretty similar amongst many samples I found. Layers of highly concentrated carbide, and ferrite.
Both form patterns, but both are created differently.
But to my main point, Wootz is just a moniker for crucible steel made from certain ores, but it is very easy to just use similar chemistries (which we do) to make the steel. Smith's have been doing that for years. What smith's haven't been doing for years, except for a very small few, until recently, was forging it correctly. That was the real mystery all of this time. That is part of what Verhoeven and Pendray figured out. However, despite the years of research and their papers, some specifics on how to do this were intentionally left out of any video, book or paper published.
It's taken a handful of us years to finally pull proper patterns through correct forging. It took a long time sort out the methods to doing so, which is where the actual magic occurs (ingot chemistry is a purposeful distraction).
The blade in question looks like alloy banding in mild steel that has high Manganese maybe. Manganese is notorious for this. I've had it happen myself, on accident. Or it's wrought.
Edit: I should say this is my interpretation. I'm not a metallurgist.
Let's see where we go.... Read it with a little caution. I think I have the high-level points about right... but I am not an expert. So there may be some errors!
