Or search: adder, expert, actuary, figurer, computer, reckoner, calculator, subtracter, statistician
2 Syllables: SU
fiddler, listener, prisoner
3 Syllables: SUU
Christopher, insecure, minister, similar, titular, vinegar, Whitaker
4 Syllables: SUUU
legislatures
4 Syllables: USUU
Commissioner, conspirator, deliverer, dissimilar, inquisitor, parishioners, perimeter, petitioner, practitioner, solicitor

Found 21 words across 4 groupings. Skipped 11 excess words of a similar stem.