Played a couple of deity games with this civ.
Hoo boy these guys are overpowered imo, fun to play though. With the unique guild, the UGPTI and the chopping bonus Benin can settle some very productive and land grabbing tradition cities that get online quickly and are almost impossible to conquer.
After grabbing whatever land you want, you rush out infrastructure and maybe a wonder or two by cutting down any trees you can find (especially those close to neighboring borders) and defend (defensive wars are quite welcome for extra generals) until you can make the isienmwenro. These.guys are completely unstoppable. With a couple promotions they even crush tercios and still do quite well against fusiliers. They feel like super knights with all the advantages of being infantry that also get bonus exp and heal a crazy amount of hp on kill. The limitation of 8 is not much of an obstacle, even 4 of these can quickly decide a war, even on deity.
You could probably play authority (more generals and even crazier Isienmwenro) or progress (overlap city firing lines, take all the land) quite well also, but the tradition strat worked so well in the couple games I played with them I did not feel the need to try those out.
I do love how many decisions there are to be made with this civ, especially when it comes to where you put your super cities/citadels and in what order, and how to quickly remove any forests in or near your borders. I do think the first UU is a bit too crazy though, they put even cataphracts to shame.