I switched from Ethiopia to Hausa recently and they are overall just so much better. Cows with every shipment and a source of influence that doesn’t come at the expense of 30-50% of your gold income makes them much more playable. And the gaps in their unit roster are way more manageable. Ethiopia lacks viable cavalry and light infantry until age 3 which is hard to work around (yes there are Shotels, but they suck at doing cavalry things like raiding villagers and taking out cannons). I made a post more specific to Ethiopia that also covered general issues with the African civs that would also be applicable to Hausa.
Like you said, Hausa lacks standard heavy infantry, but I think a siege cavalry like the Raider is versatile enough to make up for it. With Raiders and Javelin Riders you’re pretty much covered for what a Pikeman would provide. The only issue is when facing a civ like Sweden that can shut down Raiders pretty effectively.
If you do want a pike/halb equivalent, the best prospect would be a Leopard Prowler outlaw unit at the Watchtower. It could replace the redundant Desert Archers and act something like a JPK. Similarly, Ethiopia could have the redundant Desert Warriors replaced by a Shifta cavalry outlaw that could provide effective raiding.
It’s probably not optimal but I do it anyways. And yeah, the African start is pretty intense, gotta herd, build a Granary, sell a cow to get a house and village dogs. And do that while dealing with bad pathing around the Granaries and your villagers shooting all the hunts away from them.
I think it would be preferable to just give Granaries a small cost but have them build faster and have a greater area of effect. Just stagger the starting fatness of the cows so one is fat enough to afford a Granary, House, and village dogs or just give a wagon to build the first one. Faster building Granaries and bigger fields would also ease the transition to farms which is currently extremely painful.
I didn’t realize this was the case. Raiders do have a bonus against guardians so that can offset it a little.
Now after playing both African civs I’ve got some thoughts on some of the issues with their age ups. Overall Hausa seems like there are only a few good ones, while Ethiopia has too many that are practically essential.