Presumably one of the tricky things for Cold Harbor with BBB is that it's not just the ground scale that gets compressed, but the time scale too, as you noted. And as we discussed when I visited back in March, that kind of temporal abstraction seems to be the way to handle longer, more siege-like actions – Vicksburg or Mukden, or perhaps the Taiping sallies out of Nanjing in the 1860s...