35mm would be 168cm (5'6"), which would still fit the time frame, where the average person wasn't 6' tall.
It can be harder to chack models due to posing and equipment, but all of the models I've checked fit within an appropriate range for the acknowledged 1:48 scale. If a model is 34mm tall, but is crouched down, the actual figure would be representing someone taller crouching down. Crouching down 50.8mm (2") lower than full height shifts the height of a miniature in scale by just over 1mm, and most people crouching down, and with a wider stance with their legs, will be far more than 1mm shorter and still be in scale.
The only place I've ever seen people mention 28mm is on the forum, and not in anything official. 28mm isn't a scale, and there are too many ways 28mm is used for reporting model height to call it any single scale.
If you take a range from 160cm (5'3" the average height of a Japanese soldier in WW2) up to 198.1cm (6'6" for a tall, but far from the tallest soldiers around then); you get a model range from 33-41.3mm to fit that range. All of my models are within that range.
DUST models aren't great for scale when you look at the different sizes of what are supposed to be the same weapon on vehicles, but the infantry are all fine when considered as 1:48 and actually measured and compared to real sizes.