What the hell kind of cities are you visiting?
Sure, they may be smaller. But, instead of having the same dialogue and all that [censored], everybody serves a separate purpose, or has different dialogue.
Now, let me lay Riften down:
Keerava, Talen-Jei, Madesi, Brand-shei, Balimund, Bersi, Drifla, Nivenor, Bolli, Haelga, Maramal, Other Mara Priest, Other Mara Priest #2, Talos Priest, Talos Priest's Husband, Talos Priest's son, Elgrim, Elgrim's Wife, Maven Black-briar, Hamming Black-briar, Edda, Other Beggar, Sibbi Black-briar, Ingun Black-briar, Prisoner, Prisoner #2, Jarl, Housecarl, Court Wizard, Jarl's son, etc.
Now for the shops: Blacksmith (Scorched Steel), Madesi's Stall, Grelka's Stall, Bunkhouse, Bee and Bard, Brand-shei's Stall, Meadery, Elgrim's Elixirs
I didn't even count any members of the Thieves' Guild, and I missed everybody on the docks and a few other people.
So, the cities are FAR from small.
So 20 people are a 'city'? o_0