Just a rule of thumb from my perspective (compound words are not included), such as th/t/s/z/c + /V/ + n/m:
T-
-tion/-sion (question, division, conclusion),
TH-
-than (leviathan),
-thon (marathon, python),
-thm (algorithm, rhythm),
-thom (fathom),
-them (anthem),
S-
-sm (apriorism, prism),
-san (artisan, courtesan, partisan, ptisan),
-son(bison, prison, season),
-som(blossom, bosom, ransom, transom),
Z-
-zan (azan, bartizan),
-zen (citizen, dozen),
-zam (Nizam),
-zem (chernozem, diltiazem),
-zon(horizon, Amazon, menazon, blazon, cabezon),
C-
-can (florican, pecan, pelican, toucan),
-cam (piroxicam).