I just got through my first 20-year game. I ended up with several Hackers on my team, because they all seem to have amazingly high attributes (300s-400s on each stat). However, despite looking so great, their performance on proposals, graphics, sound and boosts felt a bit...underwhelming.
My gut feeling is that you might get better results with, say, a lower-stat Writer or Director coming up with your proposal, or a Sound Eng. for sound, rather than someone with high stats and an unrelated job. Unfortunately, I didn't have much time left in my game to really test this. Does job title affect a developer's performance on related tasks, or is their performance entirely based on their relevant attributes?