New Fantasy Strategy Board Game

A few days ago, I begun planning a board game. The game is played on a 4x16 board. Each player has a castle represented by 2 "castle pieces" on each corner of each player's side of the board. New units spawn between the castle pieces.
Behind the castle are the miners, which collect resources for the players. Each player has 5 miners. The statue has 25 Health. For each 5 Health lost, a miner dies. Miners can go out of the castle, but they cannot collect resources there.
Each player has 9 types of units, which have 6 basic stats. Health, (HP) Damage, (DP) Speed, (SP) Limit, (LT) Range, (RG) and Cost. (Not determined yet) Here are the 9 units and their stats.

Miner- 5 HP, 1 DP, 3 SP, 5 LT, 1 RG.

Barbarian- 10 HP, 4 DP, 3 SP, 5 LT, 1 RG

Elf- 5 HP, 2 DP, 4 SP, 5 LT, 3 RG

Cleric- 15 HP, 1 DP, 2 SP, 1 LT, 1 RG

Red Mage- 15 HP, 2 DP, 2 SP, 1 LT, 1 RG (Spells to be determined)

Knight- 20 HP, 4 DP, 4 SP, 3 LT, 1

Horseman- 20 HP, 3 DP , 5 SP, 3 LT, 1 RG

Dragon- 10 HP, 3 DP , 1 SP, 3 LT, 3 RG

Dwarf- 25 HP, 5 DP , 1 SP, 1 LT, 3 RG

On your first turn, you get 3 miners. You decide what unit/units you want to purchase, (maximum of 2) and then you put the unit/units in between your castle pieces.
From your second turn on, you do these steps:

Step 1- Move your units. Each square counts as 1 space. You can move the unit up to the unit's speed number.

Step 2- Initiate combat. Units with 1 range can attack any other enemy unit 1 square away from them. (You can attack diagonally.) Units with 3 range can attack any enemy up to 3 spaces away from them in a straight line (unless they are 1 space diagonally from them.)All range 3 units can only attack once, unless they are next to an enemy unit.
If any 2 units on opposite sides are next to each other, you can initiate combat. After you attack, the enemy can chose to fight back or retreat. During your turn, if you want to retreat, you can. If neither of you choose to retreat, you continue to fight until either side's units are dead.
If you have 2 or more units in range of the enemy unit, you can use those extra units in combat. You just have to make all of your units, and then the enemy can attack. If the enemy has extra units in range of your units, (including range 3 units) they can use those extra units too. Combat ends when all units on one side are either dead or retreated.
If you or the enemy chooses to retreat, whoever is retreating must move their units in combat out of range of all enemy units in order to successfully retreat. (they can move up to their unit's/units' speed number) If a retreating unit is not out of range of all enemy units, all enemy units in range can attack them. Then, the retreating unit can move again. (They can move up to their speed number) This continues until the unit is dead or out of range of all enemy units.
Step 3- Purchase units. Depending on what resources will be available to the player through mining and left-over resources from previous turns, and the cost of each unit, the player will have to decide what units to purchase and how much to save. Once finished choosing what units to purchase, (limit of 2) the resources not used will be saved for future turns. Once you have decided what unit/units to purchase, put them between your castle pieces. Units you just purchased cannot be moved until your next turn.

More updates will come as the game expands. Right now, my priorities are:
1:Figure out costs
2:Figure out Red Mage's spells
3:Figure out what other upgrades, abilities, or spells I want.
4:Figure out what each upgrade, ability, and spell's cost and which ones are automatically unlocked.
5:Figure out what units to rename and figure out other factions. (I want one to be a "light army" with elves, dwarves, humans, etc., and I want another to be a "dark army" with orcs, undead, etc., and possibly an in-between faction.)
That's all I have figured out now! Please leave comments and suggestions below. I am looking forward to more thoughts!