Some people have complained there's not any new mechanics in the DLC. I'm not going to debate that, but I have found the unique bonuses of the different cultures very entertaining.

This thread is about the Swahili. I think they are very powerful and I think that is GOOD.

The Mtepe is just a transport, but two massive benefits are the long distance travel and the instant embark/disembark. This makes exploration very useful.

The Bandari is just a port, but it provides stability and influence! These are also very powerful. Especially since ports can still be built in territories, unlike regular districts. So if you're on the coast, you won't have to eat massive production cost to build them - just use a little bit of influence before attaching. And also use influence to fill the rest of them before moving to the next era. Unlike other buildings in territories, you will get the benefit of influence even when not attached (whereas production and generally food is wasted).

I'm also loving many of the other cultures which are pretty unique. So I feel there are new mechanics if you play the cultures; otherwise, none.

Now my final recommendation is: don't say because this culture is powerful, that it should be nerfed. Instead go through the old, weaker cultures and see if there's any new mechanic or buff that can be added to them. If you have multiple exclusive unique cultures, it becomes much easier to have "one million different combinations" because there will be many viable choices. In sum, NO NERF, YES BUFF.

I agree, I love the Swahili, so far my favourite culture from the expansion and I hope they aren't changed. Going Carthaginians into Swahili works like a dream.