You can wedge-fit a handle in a slip-fit eye. It's just a little fiddly compared to hanging an eye made for wedging. The Rinaldi has a proper axe taper to the bit, while cutter mattocks have dead flat bits since the cutter portion is subordinate to the hoe blade and is intended for dirt use, so it stays thin as it wears back. The Rinaldi is an Italian-style geometry, so still quite thin, but in Italian terminology the rough equivalent of a cutter mattock is literally called a zappascure or "hoe-axe" so they don't separate axes and mattocks into distinct tool classes with so significant a degree of distinction that we do in North America.