Why play an Altdorf army? it seems like they have no limitations...
That's what a theme should do to an armylist, bring limitations and preference of specific units over the other kinds!
I agree with this. I think you should try to put some more limitations in the list.
Stick with state troops and stay away from militia(free companies, archers and crossbowmen), even as detachements. A exception to this could be a small unit of huntsmen, every army has scouts to locate the enemy.
Don't use priests of Ulric. If the emperor let any of those in his army that would result in one angry Grand Theogonist.
If you want to know what magic items Altdorf can use. Look at the Cult of Ulric list. It has a list of all the items that are kept in the Imperial Vaults.
A Altdorf army is in my opinion an army sent out by the Emperor him self. It will consist of the best the Empire has to offer. Flagellants don't fit the role of higly trained disaplined troops. Thay will probably still tag allong as thay join any battle where the Empire fights chaos/undead/etc. Still I don't think thay have a place in an Altdorf army.
Use the old Outrider models and you have another reason to bring more pistolleers
.
4 Knightly orders is more then enough. I have no idea how many of these orders there are in the Empire. I don't think you will find them around every corner or in every village.
Are there really enough dwarfs in Altdorf to form a good fighting force?
I have no idea about The Moot supplieing troops to Altdorf. However if you read the story about how the hot pot was created(I love that story), I'm not to sure about them being a common sight in the army of Altdorf. Gambo told Karl-Franz, after he asked for the recipe, "I cannot tell you, it'd be a betrayal of every sacred vow in the cookbook"
Finally a friendly warning to anyone that wants to try something like this. Everything can be justified with fluff, don't just think of a reason to add a unit/character/item also think of a reason
NOT to included that unit/character/item and then see what side wins. Most people know this, but get carried away when thay start making army list and thinking up the fluff behind this. I know I do.