So, cumans and goths don’t get walls. But, with the removal of the ability to make walls, you open up ALOT of possibilities for making civilizations more asymmetric.
So, here are some examples of civilizations that could lose walls, but with some tweaking could do really well!
Mongols. They have a tech called nomads that they get in the imperial age that prevents their lost houses from reducing population headroom. If nomads became a civilization passive, then they could build a row of houses, and then put a palisade wall on the far side. This acts perfectly against a light rush.
Huns. They were nomads, and they already don’t need to build houses. If villagers could garrison Hun barracks, stables, and archery ranges (and fire out of them) then huns could lose stone walls.
Vikings. WHY DO VIKINGS HAVE WALLS. Or for that matter, architecture and masonry? Or the cannon galleon? And their monks don’t get sanctity, which means no extra hitpoints. On one hand, sanctity is something vikings did not have for sure (blood thirsty fellows). On the other hand they were hardy burly fellows who deserve to have lots of extra hp on their monks. But I digress. Vikings really could lose walls, and have their palisades buffed with a unique tech. Also… if viking longboats could act as transports… ugh… so good.
On to unique techs!
Civ bonus: Palisades have +50 extra hp and +1 armor each age, starting in the dark age.
Civ unique tech: Palisade walls are made from living trees woven together. Palisade walls heal over time.
Civ unique tech: Your palisade walls now deal 3 damage per strike to melee attackers due to iron spikes being embedded in them.
Civ unique tech: You unlocked fortified palisade walls. Palisade walls have +50% hp, and 5/5 extra armor
Pick your poison, mix and match. The important thing is that this allows the civs to be less symmetrical on something that really ought to not be controversial. Walls. Just walls