Arabelean helmet designs

Complexity:
As the soldier's rank rises, more and more  customization options become available. Common foot soldiers don't have  the time or the resources to have custom-made helmets, as this is only  reserved for the rich and powerful. As the soldier's rank rises, the helmets cover more and more of the head surface area. They also tend to 'trap in' the crown* more and more, with the end result being seen in most helmets of royal guards; the crown is fixed in an 'aggression display' position and completely covered by the helmet.
Those  working as security personnel for the royals and rich benefactors can  have their armor sets custom made, to signify their rank and social  standing. These suits of armor still need to follow a certain pattern, as dictated by the employer.

Anatomical difficulties:
*Arabelean crown consists of 3 pairs of mobile pseudo-horns located on the head behind the ears. This mobility is an issue when it comes to fitting, as crowns can vary in proportion and size across a population. Helmets can be adjusted to fit each individual, and these adjustments are done free of charge.

Personalized helmets and armor:
Those  who have deserved it, be it through birth or war-prowess, can have  their armor made specifically to suit their needs and tastes. For these  types of armor the money is the only limiter when it comes to the  complexity of armor.
A good example of a customized helmet is the Trihorn, beonging to Prince Tabernas II of House Sterkhmas. This helmet(and the suit of armor) was specifically designed for the crushing close-combat style of Prince Tabernas, Every part of this suit of armor was designed to maximize damage the wearer can do.

Nomadic-Tarterran armors:
In some rare cases, mixbred individuals(one parent is a Nomad while the other is Tarterran Arabelean) will opt to wear armor that is made out of parts made by both ethnic groups. These armors are generally made more to defend against harsh climate of the north and beasts that lurk in those territories. Having such armor is usually seen as shameful, the same way that being mixbred is seen. This type of armor comes more from necessity than choice.