Originally, the A12/14/15 engines all had a different clutch. They were essentially the same except for clamping force, but in the parts industry there is little sense in keeping three or more different part numbers for three or more clutches that all interchange.

Better to delete the weaker ones & carry one part that services everything, so whenever that is possible, that's the way they usually go.
With only one part, there is no possibility that Mr A15 ends up with an A12 clutch by accident, so no unhappy customers, the retailer needs to cary as little as a single part on his shelf to service everyone & the clutch manufacturer simplifies his product range too.

Clutches for commercial models are often the heaviest duty versions.

Back when I was a young bloke, my girlfriends family had a 1963 Toyota Tiara that they had bought new. The girls in the family had a nasty habbit of riding & slipping the clutch around corners instead of shifting down & it had been replaced twice by 1968.
I came along when the second replacement died, so I fitted a new one for a Toyota Dyna 1900 truck. The clutch pedal felt like a brake pedal & needed a leg like Arnies to hold it in.
It was never slipped again, .... ever.