Summary:

Arnorian military has largely shifted from Legion oriented armies to Company focused forces. This change came as response to most forces leaving to operate offworld and to disbandment of large portion of military. Companies have become more permanent although they can still be rearranged. Most of the Companies are usually made of Praetorians who form an elite assault squad, part of the Legion which makes a main body of the Company and Rangers who unsurprisingly scout, flank and harass the enemy. In some instances, a squad of the Sisters can join Company too, but there are a few companies who have them permanently. The transition to Companies means more flexibility and modularity. Instead of large front-line battles of Barbarian war, where Legions excelled, Arnor now faces smaller and more dispersed enemies. Smaller elite specialized forces are better suited for this kind of fights.

Arnorians are used to fight outnumbered. Skirmishes and large battles on open fields, in wilds and on battlements of their forts is what they are best in. Infiltration and sabotages are just not their thing.

Every man and woman have to absolve basic training and have an option to absolve two years military service (usually not in front lines), unless they are disabled. 

It may seem that Arnorians are using melee warfare very often, but that is not yet the case. Melee warfare was developed because of endless barbarian hordes, that charged in close. It is truth, that Arnorians are sometimes using melee in shock attacks, reeking havoc in enemy lines and with Sub-dimensional powers, the melee warfare is becoming preferred choice. Nevertheless, main tactics are still focused around guns.

Arnorian transports are similar to HAVw A6 Juggernaut from star wars and come in different sizes. Tanks are similar to Sicaran Battle Tank from Warhammer 40k. Due to industrial power being aimed to infantry equipment and overall low manpower needed to sustain such production, vehicles are more or less rarity.