On 'springs'...agree the axles won't know the difference from a weight carry point
The difference is how their weight carry (weight vs travel) curve looks like
Coil springs as the longest stroke or travel. Then leaf springs and the torsion
bars on our vehicles the shortest...though a coil spring is a torsion bar spring...
Air bladders normally has the shortest of them all. Some has steel rings to
form an accordion or bellows side to increase their stroke. Some even fold
over on themselves (involuted). There is a lever with folded/involuted air springs
that both helps it lift...but then limits their stroke
In designing...their stroke (travel/etc) vs poundage is the key component