Creating card template around mechanics?

The very first thing you should do is define this explicitly. From what I can read of your post, a "faction" is just the player's chosen team. What are the rules for how troops are connected to a faction? What are the limits on mixing and matching? If you want to make something a little bit different, you need to actually work this all out. "Hopefully" isn't going to cut it. You have a bit of a start with ogres and orcs and swamps, etc.. OK fine. Work all the rest of it out. Nobody is going to be able to tell you what to do, unless you want somebody else to design your game for you?

Then you are getting into problems with your troop cards. Well without having well-defined core mechanics, it is going to be impossible to design your troop cards. That said, 1400 hitpoints is ridiculous for a board-game. You need to make everything trackable without using paper and pencil, and you need to minimize and simplify the amount of tracking and math as much as possible for your players, or nobody is going to want to play this. Its a board game, not a computer game. "HP-bars" and the like are not concepts that are easily workable, and certainly not in the 1400-scale range.

But what happens if you implement an HP bar? Put a number line from 1 to 10 on the side of your card. Now you need to move a marker (better to count damage up from zero than down from full hps, this is because having 100% health should be default and require no state holder) and you have to do this for every card that has damage on it. How much math is suddenly involved? What about ALL the other effects that can manipulate this HP marker? Do you have to move the troop cards in any way, or put other cards on top of them? What happens if the table gets jostled and the markers all move out of place???

Now you see why hitpoints are usually kept very low at best, and for many games, you simply win or lose a unit after the conflict resolution. Minimal book-keeping. Remove states instead of implementing state-holders whenever possible.

Again, you are ahead of yourself.

Work out the core mechanics first. How are factions special, what makes them different from each other. What makes the troops special. How does everything interact at the most basic level. What is the overall aim of this game, how do all the pieces come together to achieve that goal?

Once you get there, you can start to work on the finer details of conflict resolution.

And again. If your players have to break out a pencil and paper to keep track of just a single troop's hitpoints, and there are multiple troops, then it is already a game that most people are not going to want to play. Simplify more than that, or think about making this a computer game instead if you are able to do so.

The numbers have too big of a range and will turn into a nightmare of recordkeeping. HP should be more in the range of 1-15, if that.

But if you want to keep a very detailed feel of strength and toughness, you can use some kind of threshold mechanic instead. However, this does have the disadvantage of a lot of counters that could go skittering if the table is bumped.

Every time an attack's Strength exceeds the target's Toughness, the target gets a Wound counter. This might be some splotchy red chit (or even green for the Ogre faction). Accumulate as many wound counters as Health points (which would probably be 2-5), and the unit dies. Healing a unit converts a Wound counter into a Bound Wound counter (a bandage-like chit) which still counts against the Health total until it is removed. Remove one Bound Wound counter from each unit at the start of each turn.

Your decision is then whether there is any natural healing at all (Wounds turning into Bound Wounds on their own).

Potentially lots of counters on the board, but the math is simple "is X greater or equal to Y" comparisons.