Simple & strategic card combat for Civ/Crafting game

I'm new here so apologies if this isn't the right place.

I'm designing a game, the premise of which I will elaborate on elsewhere. I need a combat system weighted in favour of the attacker, that facilitates external bonuses and plays with a fair amount of strategy and doesn't involve too much maths.

Also essential to this game (and where it differs from many Civ games) is that Military might doesn't depend on fielding a large or highly upgraded army. The bonuses in battle come from crafted items (the focus of the game) that give usually temporary battle bonuses. E.g. Crafting a Bomb allows the player to dispose the item and destroy a card mid battle. Or from Buildings such as a Bastion which grants certain defensive bonuses when defending your own territory.

So. The system I'm working with is this:

All players have a Combat Deck of 8 square cards. Each side on those cards has an Attack Number and these ascend in 1s clockwise. Each of these cards also has a Card Value wish is indicated in the centre of the card. The Card Value is always equal to the lowest Attack Number on the card. The Card Values go from 1-4 and there are two of each Card Value in a Combat Deck.

When combat is initiated both players shuffle their CD. The defender draws 5 and the attacker 4. The Defender plays two cards face up from their hand on the table side by side. In doing so they expose 6 sides but conceal 2 (the 2 sides of the cards against each other are concealed.)

Now the attacker places one side of one of his cards in his hand against one (or more if possible) of the exposed sides on the table. If he plays against an enemy card and the Attack Number on his is greater than the side he plays against then he takes note of the difference between the two Attack Numbers (his and the enemy's). He count this difference as Battle Points. E.g if he places a face with an Attack Number of 4 against an Attack Number of 2 he scores 2 Battle Points.

If the Attack Numbers are equal then the defending card is destroyed but no points are scored.

A player also has the choice to play his cards against a Friendly Side. Doing so obviously incurs no damage and can be done to conceal vulnerable, low numbered sides.

At the end of the battle, each player sums the remaining of his card's Card Values as points and the player with the most points is the victor.

With few tests this seems to play pretty well and offers about a 7/3 attacker/defender victory ratio. It is quite strategic and the drawing of the hands can play a big role in the outcome. For instance if the defender draws two 4s two 3s and a 2 he has a good chance of beating the attacker if he has say one 3 two 2s and a 1.

Hope this makes sense and I'd love to know what you think!