I tracked my own data for a while some months ago. Probably close to 1000 tributes. I spent two or three months well below my expectation value. At one point I was more than 99% confident that I wasn’t getting the correct tributes. Made a thread and everything.
Then, the next month, I was so far above the expected values that things rapidly approached the mean again. I was pulling 12, 13 and 14-kingdom tributes like crazy.
I suspect, but obviously can’t prove, that Truxton is in a similar place to where I was. People who track tribute chances and get normal/high results don’t make threads about it.
In response to someone else’s question, I have seen 15-kingdom tributes multiple times. I don’t remember seeing anything 16 or higher, but those are so rare it’s entirely possible that I wouldn’t have seen one anyway, even across months of tracking.
Edit: here’s my thread.
I was wrong about how many tributes I tracked. It was less than 1000, but easily thousands of individual chances for kingdoms to give tribute. Which, if they are all independent, is just as good as tracking tribute totals.