ASC Shipbuilding was originally formed as a separate commercial entity with it's own management, staff and facilities, personnel transferring from the submarine side of the business were even given new payroll /employee numbers. The head of ASC Shipbuilding was a shipbuilding expert specifically head hunted for the role, as were most of his senior managers. The CEO of ASC Shipbuilding was also the CEO of the AWD Alliance and experienced ASC (many of them ex Tenix and ADI) staff held critical roles throughout the alliance.
Then for cost saving reasons ASC Shipbuilding was bundled back in with the submarine side of the business and anyone with a submarine equivalent at their level was made redundant. Any function rated as cross functional rather than product related was gutted and handed over to the submarine side of the business to run.
End result AWD lost many of their most experienced shipbuilding people, ASC positions in the Alliance, including CEO, were taken over by Raytheon. Submarines and DMO had already been gutted by previous reviews and cost saving measures, were now expected to step up and replace the shipbuilding people who had been made redundant, as well as tying to stay on top of their existing complex roles. End result was Raytheon ended up putting their people in many key roles. An absolute cluster.
The biggest issue I can see with splitting ASC is in the future a future Smith, Moore or Johnston may see an opportunity to save costs by amalgamating the organization again. Swings and round about.