If we accept 28mm as being 1/56 scale, at least as far as vehicles are concerned, that makes it nearly 30% larger than 1/72, which is a hefty difference, no matter what parameters are being considered. Personally, I wouldn't even think of using 1/72 scale models with my 28's. They're just too small, particularly since most minis are bulkier than they would be in real life.