But when you look at it with the skull in mind, it makes sense
And regular brides don't. For a start, if you use a noseband, it means there's a thinner bit of leather under the headpiece just where it can dig into the poll. A regular noseband lies over the area where the nerves run along the nose. And flash/crank nosebands, especially overtightened as you often see them, mean that the horse's skin is pressed against its molar teeth.
So I put the new purchase on the boy this morning. The leather looks great quality but it's really stiff, going to need a bit of soaping I think. I did the straps at the back up loosely and he seemed OK with it all (although not thrilled at having a bit back in). So we went for a little amble and it's so far so good.
I'm not a fan of any kind of "strap the mouth shut" noseband, so I was not sure about the strap under the bit, but it just seems to support the bit really, I had it on the loosest hole
You also get some plastic bit clips that can be used to attach the bit to the D rings of the chin strap and apparently lift the bit in the mouth to relieve tongue pressure.
I bought the largest size though and the strap under the cheek is a bit snug, so it wouldn't be big enough for a draft horse or cob with a big roman nose. I have read that people have had problems with them being too small and I can see why!