That's expected, you need to download the prebuilt shaders for vulkan or build them yourself. There should be a script for it https://gitea.wildfiregames.com/0ad/0ad/src/branch/main/source/tools/spirv/get-nightly-shaders.sh

You beat me to it 

There is a theory that the Trojan Horse was a battering ram, and that the works of Homer reflect his time period at times rather than the period the stories take place, so I suppose an Archaic Greek battering ram is not inconceivable.

Whenever I open the in development game, I get this

The description makes it seems as the Greek gate was not that weak. Pure speculation on my part, but i think the boulder might be loosely based on real breaching tactics (in reality with logs or maybe even axes, but in the poem one hero with a huge rock is enough). The descriptions of the rock being narrower on one side, Hector having to gain momentum to strike, part of the Trojan force climbing the wall while the rest walked through the gate. There is also the theory of the Trojan horse being loosely based on some forgotten bronze age siege engine, but i'm not so sure of it.