There is a quote 'An army marches on its stomach', I guess today that's true but mechanisation also needs Fuel and ammunition and lots of it.
The British Army needed something to provide its resupply, Alvis having developed the successful Saracen 6x6 vehicle used the same platform to develop a load carrying truck also with an amphibious capability which served from the early 60's right up until 1993 before withdrawal. That truck was the Stalwart High Mobility Load carrier or 'Stolly' as it was affectionately known.
Revered by anyone who served on it or, like me waited in a wood listening for its quiet but powerful hum from the 6.5 ltr Rolls Royce engine as it brought our supplies. A great vehicle which was highly adaptable for carrying many adaptations in its use. Sorely missed when withdrawn and never really replaced in service.