Castellane did not come to Logistics Command through a supply officer's posting, which is the route most people in his position have taken. He came through Fleet Finance, which is a different kind of uncomfortable.
The work in Finance involved auditing the supply chain rather than managing it — reviewing what had been purchased, what had been delivered, and what could not be accounted for between the two. Castellane was methodical in ways that made other officers visibly uneasy: he kept notes, followed up, and had a memory for figures that was either impressive or concerning depending on which side of the ledger you were on. Several procurement irregularities that had persisted for years did not survive his first audit cycle.
The move to operational command was unexpected from the outside. From the inside, the Admiral's reasoning was plain: the person who best understood where the Fleet's supply chain broke down was the one who had been cataloguing the breakages for five years. Castellane has not publicly agreed or disagreed with this assessment. He has, however, reduced Fleet-wide materiel losses by thirty-one percent in three years, a figure he will cite if asked and does not otherwise mention.