Is some writing a tatics book like D.R.A.I.C.H. for AoS? It was a great read and resource, but not sure how much of it is still up to date?

There has been nothing particularly developed on the tactics within the forum itself, however Daeron there have been discussions throughout threads and you will notice HobbyKiller has started a few threads with links to his own tactica's and thoughts that could be an interesting read for you.

All are in the Age of Sigmar sub forum.