Something to remember about official names in the Second World War, is that a lot of them were only popularised by (if you ask me) the early AFV historians/authors in the 1960s and beyond. Yes, the official name of the Ram with 25-pounder was
Sexton, but that doesn’t mean it was in common use everywhere, or even anywhere. But due to the influence of those early authors, everybody today uses that name for the vehicle.
Other examples of this:
- “Firefly” for “17-pounder Sherman” — Firefly, as well as Mayfly, during the war frequently meant “anything armed with a 17-pounder gun”.
- “Achilles” for “17-pounder M10” — Achilles was the official British name for any 3-in GMC M10 whether with the original gun or the 17-pounder, but pretty much nobody ever used that.
- “Buffalo” for the LVT(2) and “Water Buffalo” for the LVT(4) — in British service, they were generally just called “LVT”.
- “Honey” for the light tank M3 — this apparently comes from some American press coverage of a British tanker saying “it’s a honey!” about a new tank he just took delivery of.
- “Wolverine” for the 3-in GMC M10 and “Hellcat” for the 3-in GMC M18 — AFAIK these are both names thought up by the advertising departments of the American companies building them.