As long as you're planning your tech paths correctly while using technology boosts and properly investing in infrastructure up to Military Science you'll stay about even in technology without building a single campus via raw population (I tend to build all of my campuses at around turn 75-95) after Enlightenment, and so Rationalism
By this point not only will I have Corps (Corps Muskets are 65 CS) but I'll have had Civil Engineering for between 5-10 turns
Usually when others hit Military Science I'm about 90% of the way there as well, but I've invested into Musket men first if I have Niter within my boundaries and luckily Siege tactics is along the way to Cav so you can put up one mean defense AND if you've properly invested into infrastructure you can 2 turn the muskets which if you're on the defensive you can then put into forts for some insanely hard to dislodge units.
THEN when you hit STEEL not only have the tables turned... but the player who focused specifically on Science will feel the edge of Army Artillery while using base units and trust me they're PRAYING for oil because if they don't get it it's another 4-10 turns to get to Helicopters (or at best Corps) for them to defend with
Something important though is which Civilizations you're against and which civ you're playing as. If you're playing against a Kongo with Stockholm+Divine Spark then you're not getting many(likely any) Great People towards Culture so it might not be as beneficial to try for it rather than just getting Science/gold like everyone else
The main use if Culture will bypass the usefulness of Cavalry usually (you can still produce them but since you get them a bit later than everyone else they're not as effective for taking someone out)
BUT the strength of getting tons of culture compared to other players is that you're going to hit Nationalism and Mobilization SUPER early +17 CS is nothing to bat an eye at. Also you're going to be getting the 3rd Tier Government (I always go for Fascism) which is another +4 CS and if you've invested into a Religion and you're fighting someone else who has a religion then you can get +4 CS from Wars of Religion meaning you're getting +25 CS (likely around +15 since they could be at Nationalism when you get to the 3rd tier govt) but add in 1 GG and you're at +20 that's a massive amount of CS difference but here's where the determining factors kick in. WHEN you get the technologies to produce TANKS, HELICOPTERS, MODERN ARMOR you have the CIVICS card to PRODUCE them AFTER you've invested into your timing push upgrade where as someone who simply spammed campuses will NOT get that bonus +50% production and when we're talking about units with production costs between 300-500 Production that's going to be a MASSIVE difference in unit output in comparison. I'd say some good numbers to go by are it's going to take the Cultural focused player around 2-7 turns to produce FIELD CANNONS when it takes the Science focused player 5-10 turns and the comparison simply scales with each era and for each unit type (Excluding those without Civic card modifiers of course)
This is something they're 100% going to feel when you hit Rangers/Artillery/Helos and the cool part is that AFTER you've invested into Culture you can then use that lead to invest DIRECTLY into Science, Gold, Production, City State Envoys, whatever you wish. Which doesn't happen in reverse (you cant invest into CPT using Science, for example)
Also, foreign trade routes are somehow impossible to survive in MP games, so Kumasi actually worth nothing.
Trade routes are literally impossible to kill if you're paying attention.
You can find this under Basic Tips, under
"
5: TRADE IS YOUR NEW GOD:
.........................................words.......................................
- Micro-management TRADE ROUTES!
You can send a Trade Route back to it's origin city! All you've got to do is left click the trade route you wish to return to the city, then left click the circular icon above a foreign unit's head!
"
Also, City-States shall be taken down. For City State only adjacent to your territory, it's really bad if your enemy got the Suzerain, especially when your enemy may be storing envoys only for a sudden shot. So it's best to take them down. For City-States adjacent to multiple players, they're easily taken down by players who do not have enough envoys. Since they are eventually to be taken down, why not take down them early?
Yes, they
should be killed. That's one of the tips in the guide under "Basic Tips"
"
10: KILL CITY STATES:
•|• Not sure why people do not do this as much as possible the bonus you'd get from a city state is less than what you're going to get from that city by capturing it, also you're DENYING the bonus to other players so unless you've got a super strong city state near you (Zanzibar/Carthage/Kabul/ETC) If it's anywhere near your main city (say within around 12 tiles of your capital) you're better off just capturing it to get the free district and yields as well as any luxuries/strategic/bonus resources in the area and you basically get free bonuses and upgrades for fighting them.
"
That does not mean however that one should not utilize a strong city state for as long as is possible: I'll keep Carthage alive until someone invests a substantial amount into them (10+ envoys) at which point I'll have received a good 50ish turns of extra trade routes and production and can remove it from the game should anyone truly wish to contest my Suzerainship.
Also you've always got the option to Liberate a captured City State for the Suzerain bonus later in the game if you're looking to utilize Globalizations +10% Science per Suzerained City State!