IFCE into Flight Ops?
You can create any kind of management structure you wish, put IFCE into Flight Ops and create a Head of Cabin Service reporting to Chief Pilot but that still doesn't answer, or address in the slightest, the question of how best to actually manage 12000+ cabin crew on a daily basis.
The issue is not management structures but creating a framework that makes the crew member feel able to engage and work with their immediate manager.
This may appear off topic but it is perhaps one component of why Cabin Crew turn first to their Union and not to their immediate Manager when work issues are encountered.