It's a weird move by the FTC.

Kroger-Albertsons together would have less than half the marketshare of Walmart. It's closer to a third if you include Sam's Club. In practice it would be even less than this, because they're planning to spin off a quarter of the stores.

The decision to set the precedent that union shops can't buy each other is also odd. If non-union stores are allowed to expand but union chains are not, that is invariably setting grocery store unions on a path to shrink even further.