A fair point! But Sears did have a reputation in its other lines for high-quality bespoke (or rebranded) production. It’s one thing to have a Kenmore that’s actually a Whirlpool, but it would be different if the Kenmore were actually made by e.g. South East Heavy Industries Production Pty Ltd. I would assume that the Die-Hard rebrands that Sears undertook were done with similar care.
That said, it would probably be easier to turnkey the whole operation if Die-Hards are actually already an established national brand that’s been rebranded.