World Conqueror 4 World Records!

I think even 4 cities is possible, my 5th was Zurich which my allies could've taken but for some reason I did.

Steel and Tristian can comment on most/least cities record strategies, which I cannot.
Armored assault and leader are required on every tank general; the damage needed to capture cities is impossible without, especially because they stack with each other and with explosives. Generals like Guderian can carry all three AND a skill of your choice, rumor probably being the best.
For artillery, the same skills as tanks are needed, accuracy and leader. Konev is Guderian of artillery in that he has these by default, so add explosives and probably rumor. Zhukov holds all three also, but cannot utilize rumor.
Infantry is useless.
Navy requires leader and explosives, with rumor being an optional but best third option. In speedruns Donitz and Nimitz are largely equivalent.
Air Force depends on which CQ you are speedrunning. Dowding is a necessity for 1&2 star countries as the 50 income per rounds is a massive percentage increase on income, but is still incredibly useful for 3 star countries; I used him for all of my records (I think). Dowding will be tied down to one city, so after the first few rounds cannot be used for actual AF, so if you need another, use Arnold.

My generals: Manstein, Guderian (rumor+explosives), Rommel (rumor+Leader), Rokko (explosives+AA), Konev (explosives+rumor), Zhukov, Donitz (rumor+explosives), Arnold, and Dowding (technology).

For larger countries, say 1939/43 USSR rumor has less utility, but having it on one general does not hurt. For instance, my 39’ record has rumor on the light tank in Ukraine (Rommel), because he takes a lot of hits early on. You could also just buy more health.
For 1 Star conquests and 50’/80’ you need rumor to get rid of those generals and higher level tanks+artillery. Also, on Guderian at least, PF is only a very, very slight benefit, so you might as well use his extra slot on rumor. For Rommel and Rokko you need leader and AA, allowing one slot each. I do not think it matters which one you put rumor on, because they are essentially the same general; I put rumor on Rommel and explosives on Rokko.
For artillery it again poses the question of “what is better?” I doubt PF is any significant benefit.

agree, it's almost unefective to put PF (without medal) in exchange for rumor for Guderian. It will be better upgrading his explosive than switching his rumor, beside i still need his rumor for 12 medal invasion. For Rommel and Roko, i agree to give different role to each of them, maybe i'll copy Tristan's Roko and Rommel skill. Thanks again.

1) No, ports do not count as a city. So you can be alive with 1 port and 0 cities. It just takes a little luck to be able to accomplish it, which is only possible if your allies are competent in the given conquest.

2) Yes, this includes neutral cities. I specifically played as Brazil which is surrounded by neutrals, including Liberia in Africa, so I took all those while the AI clashed in other parts of the map.

On the terrestrial map, there's 195 cities. So the highest city record possible is 195. I don't know how many ports there are.

Okay, i'll try Brazil'50 next, in progress with USSR, only focus in europe and africa and abandon my asian front hoping that japan will defeat my asian ally (PRC and Mongolia) then I'll take back later after I conquered Europe. It turns out that Japan can't face PRC & Mongol spam even with the help of their allies. Maybe i'll just finish it and see how many cities i can take with this strategy.

Thankyou Sir.