This position is not responsible for a third of the annual sales though. A huge portion of the annual sales is the core books. This position is a lead designer on one new book a year, which will then be reviewed by a higher up designer, and then be reviewed by a higher up editor. So while not insignificant, it's about the same level as most of the other hires they'e made for art and content and editing over the years. That doesn't mean those people are as important to your personal interests - you may not be as into the art and editing and formatting and such as you are the design. But in terms of the D&D team itself, this is not on the level of "one third of the entire team's responsibilities". It's not even a management position as far as I know.
And understand where most of my difficulties are coming from is the ongoing claim, which as far as I know you've never made, that WOTC's D&D team is operating on "a skeleton crew". That claim has been made by several people here at ENW, and it's a false claim. The D&D team is much bigger than it used to be. And making a huge deal (130 posts so far) out of ONE new non-manager designer being hired just helps those "skeleton crew" claiming people reinforce their argument.
Which is what I am really after here - let's not reinforce that "skeleton crew" claim by making it seem like hiring one new non-managerial designer is hugely significant to the D&D team overall that it's like adding another 1/3 more of the team. That wasn't the intent of your argument, but I can guarantee that's the spin some others will put on it.
The position is meaningful. But, it's also in the context of a much larger team than what used to be at WOTC for D&D. Just because this one was done through a community appeal, doesn't mean all those other hires WOTC quietly engaged in through their normal HR department are diminished either, or that somehow this hire meaningfully increases the number of people working on the D&D team.
I am glad they hired someone for this position, and I think this person will be good in the position. Just, don't reinforce the trolls out there claiming D&D is operating on a skeleton crew by shooting off fireworks over a single hire like it's taken three years to hire one new person to the team.