2 Syllables: SU
anno, ano, arrow, backbone, Barrow, Blackstone, Buenos, Castro, Cato, credo, facto, fallow, Gladstone, Glasgow, hallow, halo, Harrow, macro, Mayo, narrow, Palo, Paso, Pedro, Pharaoh, Plato, Plato's, rainbow, sallow, scapegoat, shadow, shallow, tallow, Tasso, waistcoats, Zeno
3 Syllables: USU
4 Syllables: UUSU
5 Syllables: UUSUU

Found 55 words across 4 groupings. Skipped 4 excess words of a similar stem.