Or search: crook, felon, oates, fawkes, plotter, criminal, conspiracy, machinator, confederacy
2 Syllables: SU
fiddler, listener, prisoner
3 Syllables: SUU
Christopher, minister, reasoner, similar, theaters, theatre, Theodor, titular, vinegar, Whitaker
4 Syllables: USUU
Commissioner, conspirators, deliverer, dissimilar, inquisitor, parishioners, perimeter, petitioner, practitioner, solicitor

Found 23 words across 3 groupings. Skipped 11 excess words of a similar stem.