The Flagrant Vandals feared Hafner for a very good reason. As a border territory of the Vesia Kingdom, the Hafner Duchy differed a lot from the interior duchies.
First and foremost, their main responsibility was to guard the border. Military priorities came first, everything else came second. Thus, it did not matter too much if the border star systems failed to turn a profit. As long as they maintained a sufficient garrison to deter pirate raids and the like, it was fine if they lost a substantial amount of money over time.
The Vesian propensity for infighting was remarkably subdued in the border territories. It was the same at the Bright Republic's side of the border. With the threat of external enemies so acute, the noble Houses that controlled the border systems had no time to wage pointless rivalries amongst themselves.