This was the infamous Whitbread Umbrella where they bought up shares in various breweries supposedly to protect them from hostile takeovers then took them over. Those you mention plus many others (Castle Eden, Flowers, the one in Tiverton - Knight Starkey & Ford? etc) were included, although Wethered of Marlow was owned by Strongs and were later to be called "Whitbread Wessex". A sore subject for me as I lived in Romsey when Strongs was taken over.