Deanna Troi - stiffer than a plank of wood?

[Takara_Soong 4]

I agree she shouldn't have been promoted to full Commander just by passing the test, unless maybe she had the time in rank / time in service combination to merit such a promotion and that test was the only thing holding her back. (This is a possibility however. She did say that some people from her graduating class had already achieved that rank.)

There were many others who had more time in service than she did and would be more qualified to hold the rank of commander than she was.

 

According to st.com, Troi graduated from the Academy in 2359 and then went to study on Betazed until at least 2362. She was assigned to the Enterprise in 2364 and had the rank of lieutenant commander*. She became a full commander in 2370. Compare that to Geordi who graduated from the Academy 2 years before Troi in 2357 and still hadn't made it to the rank of commander by 2379 (the year Nemesis was set). I won't even go into the unfairness of Data not making that rank after all of his years in Starfleet.

 

*I'm going to assume that those who went on for advance degrees were given higher ranks upon graduation than those who went straight from Starfleet Academy into service because that is the only way to justify Troi being a lieutenant commander so quickly.