The scale thing came up in another thread a while back. I think that was me too
So, background and history, a quick primer, as it's always worth clarifying.
Airfix figures, plastic, nominally 1/72 / 1/76. Realistic propirtions and some 'chunky', like the Napoleonic French. 1/72 works out at about 20mm, metal figure wise
In the'seventies you get metal wargames figures appearing, called 25mm, basically an inch tall. You can get larger armies in the same table space with smaller scales, hence the appearance of 15mm (1/100 ISH) 10mm (1/144 ISH), 6mm and smaller like 1/300th. One company invented 1/285 for a slightly larger, more detailed ‘1/300'
And so, by the same reasoning, we get 28mm. 25mm mutated into that thanks to the appearance of the chunkier figures in the 'eighties from Guess Who and others. Then came the foot-to-eye thing, apparently so there was some kind of consistency in comparative sizes. Is a Napoleonic figure with a tall shako the same'height' as a WWW2 figure in a soup bowl?
Anyhoo, where does 1/56 come from. Well, 25mm used to be about 1/60th. So, we get this weird figure. Arbitrary? Kind of. It's ball park. This does mean you get inconsistencies. Look for my comparison of the Perrys Morris CS8 radio truck and the Warlord CS8 GS. About as different as 1/72 to 1/76,
Airfix to Esci, while the A13 cruisees from Blizkrieg and Warlord are identical.
Cue They Might be Giants song 'Actual Size'
Many wargamers don't worry too much to comparative 'scales' so long as they've got the gear they want. Igot some British BEF BSA motorbikes which were '28mm' AND 1/48. Painted and sold because they looked too huge
Figure wise I've gone for 'chunky' for Europe and 'realistic proportion' (Perrys) Western desrt
So, I go for consistency in size by theatre
Thinking about it, '1/56' may have first appeared when Italeri started a plastic kit range for Warlord with a Firefly