Robert Comsol wrote:
"Balance of Terror" did establish that in Romulan society good connections to TPTB can outweigh rank and performance:
DECIUS: Only in code, Commander. To inform our Praetor of this glorious mission.
COMMANDER: Your carelessness might have ended this glorious mission. You're reduced two steps in rank. Return to post.
CENTURION: Take care, Commander. He has friends, and friends of his kind mean power. And power is danger.
If the above quote is your evidence that "good connections to TPTB can outweigh rank and performance," then I respectfully say that that's entirely conjectural speculation on your
part. The way I read that quote, all it says is that Decius may get someone to enact retribution on the commander for reducing him in rank. It doesn't say anything about said friends helping him to rise up in rank.
There is no reason to assume that this has changed by the 24th Century, on the contrary Sela's young age with her father being a general strongly suggests that little or nothing has changed.
And that's also speculation on your part, as there was no evidence whatsoever that Sela got her position because of her father's influence. All she said was that he was influential enough to save Tasha from death.