Nice treatment of the roofs and the timber walkways!
I had a go at one in 15mm - basing it more on the earlier Sengoku-Jidai mansions than the post 1600 castles familiar today (There's a lot more earthworks and timber, and a lot of open bamboo fencing a la 'Ran'). My internal buildings will be simpler with wooden shingles weighted with stones and horizontal lathes, a feature of peasant houses, rather than fancier tiles, but the key is to get the proportions right. All houses were based around number combinations of the tatami matting.
Apparently some of the best preserved examples/recons are in Korea. I can thoroughly recommend Stephen Turnbull's recent offerings on Japanese castles, early and late.
This is quite early in the build. I had the additional problem of making the supports for the timber walkways wide enough to allow the multiple-based figures underneath. Not a problem with individual basing.
A view of the fencing and wooden hoardings, with beginnings of the Tenshu mound (actually quite a small structure is planned)
The main gateway will have extensive 'ironwork' on the doors and 'plaster' fireproofing