@ 500 Fleet credits each, these officer are not cheap.

Bought 30 Engineering today: 17 turned out to be flight deck crew, 3 transporter operators, and 7 misc operations.

ONLY THREE were actually Engineering Personnel.

Are they misclassified? Or did we miss something in testing?

I think it's something to do with the amount of engineering doffs vs operations doffs. If I remember rightly, operations has far more different careers than engineering, so when it comes time for the game to look down the list of possible doffs to reward it's just more likely to pick an operations doff.

Also it seems to prejudice towards rewarding the more recent special doffs, like flight deck officer and space/ground warefare.

There are three departments each with two branches.

Tactical (the red shirts) is made up of tactical and security doffs.

Science (the blue shirts) is made up of science and medical doffs.

Engineering (the gold shirts) is made up of engineering and operations doffs.

As Orondis said STO has a tendency to give out the new doffs more, which leads to getting lots of Ops, Science and Tactical doffs.

Pity.

In truth I'd be happier if I could choose what I was looking for, even if the cost was substantially higher. While requesting random crew seems good from a game mechanics perspective (I don't know how it would / sarcasm), it would be more fun if we could choose the crew we actually needed.

I know in the US Navy they have a surplus of chef's on their Carriers because of RANDOM crew referrals. Makes total sense.