It seems that people have very different approaches on how to play this game and that's probably why everyone finds different specialists more or less useful. Since many specialists (and especially combinations of them) can be used in so many different ways I think it's really hard to balance them out based on ones own personal experience. Your play style determines the subset of situations you often end up in and thus some specialists seem never useful.

The easiest change to the game to make it fairer would be a game option that gives every player the same hiring choices.

I circumvent the problem of bad hire options to some degree by not promoting specialists right away until I get bad hiring options.