Ann: Intention to demerge Coles - Briefing Presentation, page-64

I have a problem with your maths. You assume that splitting the owner ship of the entity means it's owners split market share (eg, WES holding onto their 20% share somehow provides another participant in the market). From a retail side of things, there would be a loss of a major participant (but a smaller one growing).

Given the cost of living being a big issue with 'battlers' (or families living beyond their means depending on your perspective) in the media I don't see it being politically palletable for any government to allow consolidation in the industry. A take over would likely have to come from a new entity, such as private equity, to be allowed I suspect.