I probably don't have enough proof, so if you want to believe, believe. If you don't want to, don't. I don't care if you do or not, but I'll just post these screenshots. I firstly made a map, to see if I kill a big stack of generals, would give a lot of SP *I have no evil intentions, just testing lol*. Then I started to find bugs and try to go through water, until I did it, somehow.
Here's the stack
Here are the units, they are default ones, but I added one unit "OP Infantry", with 150 attack/defence, 100 critical, 100 range, 10 cost. Nothing else. The 2 cities are not ports.
I'm still trying to find out how I did it.