basically blitz looks like a mobile game and seems to have balance issues as you can win a match at the flick of a switch. i was losing a game 170 to 3 and i won in the end 170 to 200 just because i spawned a level 2 scarab.
i feel like the cards are a good idea and if you can get them through more means than just playing blitz and the card aspect stays in blitz then thats good but allowing people to pay for packs that will increase the effectiveness of cards then being able to pay your way to the top seems like a bad idea especially as this is a full title
im not saying that give all the cards or remove the upgrade style of them but dont make it a necessity to pay for pack to stay with everyone else in the terms of balance because if your army goes up to a similar one it depends on who spent what not whos the better player
maybe when upgrading cards instead of increasing health or damage unlock the option of a different variant of that character like grunts let you unlock suicide grunts and hunters into ironclad hunters and so on and balance them so it is not needed to have the ironclad over the regular hunters
just some thoughts on how things may need to change if the game wants to have a steady player base instead of one that died and became populated with wales that spent money to get the best of the best equipment