Upgradable battle cards

There is a huge problem whit the current battle cards system: There are many battle cards, but only a few of them are actually usefull, if compared to flat stats battle cards. 

Each battle card is consisted of 2 concepts: the range and its bonueses. Currently, the bonueses for some battle cards are so weak and innefective that the ranges of the battle cards or flat bonueses battle cards are oftenly more important than the bonus provided for non-flat bonueses battle cards. 

This leads people to prefer utilize those battle cards for its range concept, or simply alternate to flat bonueses battle cards that are generic and benefic to almost every battle.

There are currently two types of battle cards in game: Battle cards that are usefull in specific situations (Destroy 2 crew per hit / 70% extra crit damage / extra damage per ship on enemy flotilla) and so on. these specific cards, i believe, are useless in most situations of the game, except for very especific situations that rarely occur in game. 

The problem is, oftenly even in those situations these battle cards are rendered useless by flat bonueses battle cards, because those battle cards are simply so usefull and straightfoward they can be applied at pratically any battle, and reap a huge reward from each of them.

For example, you start whit post op analyzies (25% extra xp) , a card that gives you 75% extra shield potential and -10% hp, and another card that gives you 55% extra armor and lots of close range attack opportunities. 

If you pay attention , together, these 3 battle cards, should consist the deck of about 75%+ of all the players in the game because, they are simply very, very effective. 25% extra xp for every battle you play? you can use this almost all the time to level up your hero and make your fleet FAR stronger after battle. 

55% Extra armor + short range defense? the best choice for a full flak fleet against the enemy! how could you lose if the enemy has the same fleet type to you and he uses a different tatic?

Extra shield and long + medium range? the best choice (for a while) if you have a missle fleet or the enemy has laser weapons at his disposal. 

What im trying to explain is, together, all these battle cards, only 3 of them, have enough potential to render other battle cards useless, in most situations, except for extremely key situations in game, like you want to destroy the enemy man power to survive. 

That means: only a few battle cards are usefull in most situations. and whenever you research new battle cards in the technology stages, they rather feel useless or you simply research those upgrades because "they provide a good shield" or something like it. It is necessary to make all battle cards usefull in most situations, so you could feel the sense of collecting battle cards that actually change the flow of battle, and help you to win the battles you need. 

Why have so many battle cards if only a few are actually usefull to be played in most situations of the game?

So, in order to solve this and make most battle cards usefull in all situations of the game, we could use the Research Tree of the game and the different stages of technologies to create, instead of battle cards that are usefull only in specific situations and end up useless in 90% of all the cases of the game, we need to use this research tree stage to give players different initial battle cards that are upgraded as players research different technology stages of the military techs and keep upgrading their battle cards efficiency. 

That way battle cards won't be useless in some situations and usefull in anothers, every single card will have its place in game. There will be battle cards for late game, for mid game and for early game. And all of them will be usefull, in their on way. 

but in order to do that, we need to estabilish some sort of "battle card galactic law" in order to balance all the battle cards so some of them are not excessevily stronger than others or rendered useless by another battle card, and i believe this law would be:

All battle cards should utilize flat bonueses that are upgraded for researching its specific technologies on higher stages, when initial battle cards are replaced for weaker versions of such.

For example, the initial battle cards every player would have when they start a game, would be something like... 

15% extra armor strenght on ships(Lane 1,2,3 respectively: Medium- Short - Short) 

then 15% extra shield on ships (Long - Medium - Short)

10% extra crit chance on ships (Medium- Medium- Long)

10% extra xp after battle (Short- Long- Medium)

For example, these types of battle cards will be availble when you start the game. and as you progress trough the different technology stages and research battle cards tech, you will upgrade your already owned battle cards to something like this:  

Post OP analyzies II: 20% Extra XP on fleet after battle

Post OP analyzies III: 30% Extra XP  on fleet after battle

Post OP analyzies IV: 50% Extra XP on fleet after battle

and so on for different technologies techs. that could help to make all battle cards usefull in all stages of the game, and make these battle cards have a higher impact on the game whiteout harming the strategy of space battles and simplifying things up. 

Also you will only upgrade battle cards when you research the requeired technology on the military stage, that is divided by different tech stages, and each stage above featuring a upgrade of the previous battle card.

so according to this logic, each battle card would be upgradable until tier IV, which would be correspondent to the technolgy stage 5 of military tree.

Note: The bonuses for these battle cards need to grow in a small, bug signant amount of bonus % in order to incentivate people to research advanced technologies of the same kind, so those upgrades seem more singnificant to research and not useless to "upgrade" in the next technology quadrant.

The new battle card system

I believe it would also be necessary to implement new battle cards for each technology stage, and also rework a bit the battle cards found by doing curiosities. 

Here is a simple sketch of how these new battle cards would look like :

Curiosty related battle cards 

The concept of curiosity related battle cards is that, battle cards that are usefull in specific situations of the game. be it mid game, late game, or early game. these extra battle cards cannot be upgradaded in different versions and are inteded to improve the strategical gameplay of the game even further.

Example curiosity tier 2: enemy fleet has less CP threshold than enemy max CP: 40% extra fleet damage if CP threshold is 30% or lower, 30% extra damage if 50% or lower, or 20% if 50% or higher Reason: Ability to utilize enemy weakness at your favor.

Example curiosity tier 3,4: 200 Extra dust and science per Medium Ships destroyed. 400 Dust and Science once tier 4. Reason: Medium ships Weapons can be scavenged for dust, and used as a research tool.

Example Curiosity tier 4: 1000 dust and scienct per carrier ship destroyed. Reason: "Something" Found scavenging Carriers that is worth alot of dust, and may help scientists to research?

Unfortunally i haven't thought up more possible battle cards to be researchble trough curiosities. If you are willing to help me and got a idea of what battle card we could include in the game, state it below in the comments section. I'm all ears! :)