There are some things missing in the process of constructing/creating a monster. Artificial intelligence type or AI type was quite easy to add. It was determined from the monster family and/or type of the monster. It's later used to make decisions about how the creature will act in certain situations.
Skills and default items are still missing. Some skills can be determined from the profession, but default item set is a problem. You could determine them from the profession and type of the monster, but instead of that I was thinking to add a new AI module fighting style. That way let's say a human fighter could have several styles with weapons and armour selected for that particular style. Not only items, but you can then determine combat strategy and also some additional starting skills from the style. Besides you need less fighting styles than there are professions and monster types.
Fighting styles need random variation in weapons and armour to prevent static item sets. It's going to be a complex system which is only telling how even one small area of roguelike is incredibly difficult to program. There is no easy way to do this, you need to create a number of styles with proper items, but still maintain random variation.