There\'s no reason whatsoever that you shouldn\'t have a Hochland army. As far as I can remember fluffwise Aldebrand Ludenhoff is still alive and kicking and has the remnants of the Hochland contingents with him. Also there\'s no reason you have to do a post SoC army, the current Chaos mortals book seems to have it\'s timeline set to just before the SoC and there are plenty of historical characters feature in rulebooks, Vlad von Carstein for instance.
f you want info on the post SoC Empire
Sigmar\'s Heirs, the WFRP sourcebook for the Empire, is a mine of useful background material. It even gives the names of the barons etc. in each province and lists the largest towns and villages and their population. I found it extremely useful in planning my Ostermark army.
Edit: I just went and had a quick look at my copy and most of the towns and village entries for Hochland are 0 (population missing). Hergig\'s original population of 9200 is now approximately 500 but Ludenhoff has returned from Talabheim and is rebuilding the city.
A good way to represent the ravaged state of the province could be to include lots of flagellants and doom-crazed nutters who have lost everything except their lives to the invasion and gone mad as a result.