Which Ulm national units should I recruit?

[PvK]

I think all the units are good, and though best used in the right circumstances. Morningstar or hammer depends on whether the enemy has shields or not. Shielded or unshielded depends on whether the enemy has lots of missile weapons or not. Full plate versus chainmail depends on whether you have more time and resources and a strong enough army, or whether you have more gold and need to grow your army as quickly as possible.

Arbalests don't mix as well with heavy infantry as shortbows do, because shortbows generally don't hurt if you shoot your own men with them.

Templars are good if you have a good bless bonus. They're much cheaper to maintain than black knights.

PvK