Revisiting some old ideas

I'm not seeing this problem with side by side comparisons. Can't you just click back and forth, and the box would be right on top of each other for even easier comparison? Putting 2 boxes of tabs right next to each other would be silly, but maybe that's what you want?

That would actually be a bit harder. The reader's focus would have to leave that area of the chart to find the right tab and click it. Right now, we can get consecutive ranks on the screen simultaneously, and we don't even need to move the mouse. The difference in effort isn't much, but the effort we'd save the reader by switching to tabs is even less; on typical modern monitors, you need to scroll just to get to the summary chart anyway.

Not much to say about the navigation page at the bottom, other than it's been needed for a while now, but for storyline quests and skill pages in particular (and a few more than I can't think of off the top of my head).

Just a few things I want to bring up about the tabs though. While it's true that tabs break anchors, does it really matter whether or not anchors work when you're using tabs for this specific topic? I highly doubt that there will ever be a need to directly link to/reference rank x of skill y's training requirements from another page. I thought the whole point of same-page anchors was to help you skip the unrelated text, which tabs are better at doing. You could have it anchor to the training methods section and click the rank you want to see, shortening the ToC considerably with the drawback of requiring one additional click.

As for looking at consecutive ranks... while the current layout allows for side-by-side comparison, what if the reader only cares for one rank in particular, or wants to compare rF to r1? It'd be 1-click versus scrollscrollscroll for the latter.