My understanding is that the smallest sprocket you'll fit onto a 5x74mm PCD crank is a 24 tooth (see, for example, here). The 22 tooth sprocket would require a crank with, for example, a 58mm pitch circle.

My LHT came with a Sugino triple. It uses a 5 bolt 74mm PCD for the inner (smallest) sprocket, and the middle and large sprockets attach to a 110mm PCD. That means I could change the 26 tooth inner for a 24 but not a 22.

Please correct me if I'm wrong. :-)

Cheers, A.