The tunneling issue makes sense. The wall will be much more stable because of the greater base area, and the sappers will need to dig a much bigger cavity under the wall for all the additional material to fall into - if the holes too small the wall might not collapse well enough for the ground forces to have a good opening to assault.
The second point is less convincing though. Forts and castle walls had mitigation for that extra issue - machicolations are an example. Often, arrows wouldn’t be used for killing the people right at the base of the wall, instead rocks or hot sand would be used to fuck up their day. These also took out armored units - rocks just, well, crushed them, and hot sand got in the gaps and visors and burned the shit out of them. They could also often not get rid of it without taking off the armor, so they just burned till the sand cooled down.
Also arrows were a manufactured commodity. Rocks were just taken from the land, or could be waste from quarries etc, and sand is rough, coarse, and everywhere.
So it’s not walls then I suppose. Just the slopes of a flat topped pyramid like thing. I mean, it still provided a height advantage, but it feels like they have lesser cover from arrows than they would have if it was like a conventional wall.
I read a lot, and currently I read with calibre on my pc since I can highlight and export them directly so I can include them in my notes. I’d like it if I could run the calibre server and be able to higlight on my phone, and sync it over to my pc automatically.