About a marillion years ago Tarmac swapped its housing division (McLean Homes and Tarmac Homes) for George Wimpey's construction and minerals divisions, and Carillion was the name given to the new construction outfit when Tarmac decided to demerge the construction arm some years later. I left the new housebuilder for pastures new and years later worked for Taylor Woodrow which then amalgamated with (but effectively got taken over by) Wimpey to become TaylorWimpey. In the meantime Wimpey had devoured Laing Homes and Alfred McAlpine, while Taylor Woodrow had consumed Heron Homes, Bryant Homes and Wilson Connolly. The construction (non housing) company that was left was later acquired by Vinci.
So the simple answer to your question is the whole industry has run out of proper names and meaningful logos, due to years of incestuous carnivory.
HTH, if not then WGAF!
BTW watch out for Vinci to come to the rescue, everything will be glossed over, probably in some sort of mysterious coded gobbledygook.