Now that we're at Week 4, most of the main combat and defense roles have been met. You've got your main champions, your ranged support and the general infantry mixed with good range.
The common Necromancer would find most of their defense needs met at this point, but the summoner here is clearly no common Necromancer!
Now that a standing force can dissuade the vast majority of low level paladins, there is time to consider what long term success might look like. The gap between being a frightening rogue necromancer in the valley and a well respected lord of the dead is a large one, but I've got my hopes that this summoner has a good vision.
We might see a resurgence of subjects like Art, Diplomacy, Tourism and Baking amongst these skeletons if the town can get built up enough. :P
Best of luck!