Dragon Army + DragonFactory

using System;
using System.Collections.Generic;
using System.Linq;

class DragonArmy
{
    static void Main(string[] args)
    {
        int dragonsCount = int.Parse(Console.ReadLine());
        DragonFactory dragonFactory = new DragonFactory();
        var dragons = new Dictionary<string, Dictionary<string, Dragon>>();

        for (int counter = 0; counter < dragonsCount; counter++)
        {
            string[] dragonArgs = Console.ReadLine()
                .Split()
                .ToArray();

            Dragon dragon = dragonFactory.CreateDragon(dragonArgs);

            if (dragons.ContainsKey(dragon.Type) == false)
            {
                dragons.Add(dragon.Type, new Dictionary<string, Dragon>());
            }

            dragons[dragon.Type][dragon.Name] = dragon;
        }

        foreach (var type in dragons)
        {
            double averageDamage = type.Value.Values.Average(x => x.Damage);
            double averageHealth = type.Value.Values.Average(x => x.Health);
            double averageArmor = type.Value.Values.Average(x => x.Armor);

            Console.WriteLine($"{type.Key}::({averageDamage:F2}/{averageHealth:F2}/{averageArmor:F2})");

            foreach (var name in type.Value.OrderBy(x => x.Key))
            {
                Console.WriteLine($"-{name.Key} -> damage: {name.Value.Damage}, health: {name.Value.Health}, armor: {name.Value.Armor}");
            }
        }
    }
}

class Dragon
{
    public Dragon(string type, string name, int damage, int health, int armor)
    {
        this.Type = type;
        this.Name = name;
        this.Damage =  damage;
        this.Health = health;
        this.Armor = armor;
    }

    public string Type { get; }
    public string Name { get; }
    public int Damage { get; }
    public int Health { get; }
    public int Armor { get; }
}

class DragonFactory
{
    private const int defaultDamage = 45;
    private const int defaultHealth = 250;
    private const int defaultArmor = 10;

    public Dragon CreateDragon(string[] parameters)
    {
        string type = parameters[0];
        string name = parameters[1];
        int damage = parameters[2] == "null" ? defaultDamage : int.Parse(parameters[2]);
        int health = parameters[3] == "null" ? defaultHealth : int.Parse(parameters[3]);
        int armor = parameters[4] == "null" ? defaultArmor : int.Parse(parameters[4]);

        Dragon dragon = new Dragon(type, name, damage, health, armor);

        return dragon;
    }
}