Ok I haven't tried inserting screenshots before so hopefully this works
But anyway, I figured I would show what happened in a game I just started today with Kongo using the warrior only strategy.
Here is my starting position.
After starting, I explored a little to the west, found no AI there, and then moved east with my initial warrior. Before he got too far east, I had a second warrior and both of them proceeded past the science city state shown in the below screenshot. I found Alexander and started preparing for an attack. My two warriors waited there until the 3rd one came close. Then once they were all in range, I declared war on Alex and took the city you see them currently around/at. He had a builder there that I also stole, and as you can see there was iron there as well. (Though you don't need iron to build Kongo's swordsmen, it does help with boosting the research for them a LOT). I had been simply rushing iron working the whole time, and once I took the city pictured and used the builder to mine the iron mine, I only had 2 turns left before I got iron working. Also, after I had finished my 3rd warrior I built a settler and settled the city to the far west there. This was all at turn 34.
Shortly after this, I finished iron working and upgraded 2 of my warriors to swordsmen (while waiting for enough cash for the 3rd). By then, Alex had settled another city slightly to the southwest of where my 3 warriors were. At this point, I thought it was unlikely that I could finish off his capital before he might be able to get some archers and/or walls going, so instead I went and took that city he settled slightly to the southwest. After that, I upgraded my 3rd warrior to a Kongo swordsman and forced Alex into a peace deal that gave me a ton of gold. Then I moved all 3 of the swordsmen FAR down to the southwest where Japan was starting to encroach on my territory. In the meantime, I started building walls and chariots in the cities I just captured from Alex (which of course came in very handy later when I upgraded the chariots to knights when Alex tried to attack me later to get his cities back, and of course I completely crushed him.)
My 3 Kongo swordsmen traveled way way way down southwest and easily took the city state that Japan had taken over (you can see it is Lisbon in the below picture, on the far left side). It had like 20 defense still and was blown up immediately by 3 swordsmen. In the meantime, I was pumping out tons of settlers from my capital and settling everything within my region that was good. Eventually, I extracted a peace deal from Japan where he gave me all his gold. At this point, there were some barbarians slightly distracting me so I couldn't march on Japan's home region fast enough to do more damage to him. However, by then my empire was already pretty huge. Here is what it looks like at turn 93.
And here is the menu screen so you can see I was playing on Deity. Also, this is on HUGE map.
As you can see, until I built those chariots at the cities I took from Alex,
I didn't build any military units other than 3 warriors!! And I had to march them 15 spaces to Alex's territory, and then probably at least 22 or 23 spaces back in the other direction to take that city state from Japan, and I still was able to beat both of them up very bad and set up a nice large empire for myself by turn 93.
