I think they are fine.
Depending on what the cost is for their unique units, the idea of them generating gold to recover the cost works for them. I am very curious IF the foragers’ bonus is basically similar for Malians, but for food. (more food and longer duration for those)
What it can be OP is the HP bonus, even if a Skirmisher will get taken down +1/+2 hits later. As long as they lack certain upgrades, I think it can get balanced.
I am very curious of this interaction between Mapuche and Berbers, because as far as I know those 2 civs have the only techs that affect team castles alongside theirs. Also, the wording suggests that it can also affect UUs in other military units. (Huskarls and/or Tarkans and/or Condottieros)
As for pass-through damage, which I have planned for a civ concept that’s in the final phase, I think it will be a low percent, akin to Gurjaras’ Chakram Throwers.