Was T'Rul anything more than a technician, though? She was sent to babysit a cloak, and probably ferry intelligence reports to the Empire. What about that job suggests she would rise to a higher rank that would lead her to being a liaison coordinating military activity?
She held the rank of sub-commander, so she was clearly more than a technician.
Why? At best it might make her the equivalent of Geordi LaForge, an expert on the technology side of things, but not necessarily groomed for command and diplomacy.