I would hope that this is exactly the right forum to for this approach. Acknowledging that their own "impact per working hour" is probably less than Bostrom's... is the least I would expect from someone claiming to honestly evaluate their own skills.
I agree that the approach as summarized by you isn't very appealing, but to me the ad doesn't read like this. It's a difficult job to do well, and can be prestigious. Whether it is depends on the framing you apply.
If funding were available, the Centre for Effective Altruism would consider hiring someone to work closely with Prof Nick Bostrom to provide anything and everything he needs to be more productive. Bostrom is obviously the Director of the Future of Humanity Institute at Oxford University, and author of Superintelligence, the best guide yet to the possible risks posed by artificial intelligence.
Nobody has yet confirmed they will fund this role, but we are nevertheless interested in getting expressions of interest from suitable candidates.
The list of required characteristics is hefty, and the position would be a challenging one:
The research Bostrom can do is unique; to my knowledge we don't have anyone who has made such significant strides clarifying the biggest risks facing humanity as a whole. As a result, helping increase Bostrom's output by say, 20%, would be a major contribution. This person's work would also help the rest of the Future of Humanity Institute run smoothly.