Keep the brands that make the combined business clearer
Portfolio rationalisation should make the combined business easier to understand, not simply reduce the number of logos. A masterbrand can bring businesses together when separate communications conceal the breadth of the offer or leave customers unclear about how different capabilities connect. Teledyne brought multiple healthcare businesses under one brand after customers struggled to see the full range and adaptability of its offer.
Established brands can still be worth retaining when they carry useful reputation, customer confidence or specialist heritage. Following an acquisition, Toshiba created a new go-to-market brand that built on the acquired IBM business's reputation while establishing a distinct identity for the new organisation. The practical test is whether each retained name helps customers understand a meaningful offer, or adds another layer of complexity.
Sources: Teledyne Healthcare: Bringing multiple brands under one roof, Toshiba: go-to-market brand, employee engagement and advertising campaign