Sure, but there are many shades between perfect mechanistic systems and total freeform. I just kinda think the card system leans a bit too much toward the former, but I'm not advocating we should move completely to the latter.
Maybe I'll give a very short example of how the system I had in mind might work (just a very quick example, I'm not caring for balance or completeness here). There are, of course, a myriad ways in which this could be altered, so don't go pinning against details or imbalances here.
Name/personal info
attack: 1d6
How good you kill things.
minimal defense: 4
How difficult you are to damage, increased by things like being dexterous to avoid attacks or armor to tank attacks.
Maximal defense: 8
How much you take before the grim reaper pays a visit.
stats:
speed/dexterity: 0
How quick you are on your feet or feet-like appendages.
endurance:0
How well you roll with the punches and take hits. Also how many jello shots you can hold up.
magical affinity: 0
How good can you wizard. Do you even conjure bro?
You get 10 points to allocate to stats. You can't directly increase attack or defense values, but these are modified in combat itself through various means.
(Could also say that, for example, base speed divided by 4 is added to attack and defense values so that higher stats directly give you better numbers. That'd be more complex though, so up to gm discretion.)
Getting hit above your max defense and it's game over. Hit between min and max and you suffer damage, lowers max defense and/or maybe min defense, depending on type of damage.
Unarmored: run around butt naked in the apocalypse, why don't you.
No bonus or malus. Free as well.
Light armor: Doesn't hinder the wearer in any way. Doesn't really protect him either though.
Add 1 to minimal defense but nothing to max defense.
Cost: 2 shekels.
Medium armor: Good set of protection, will stop a weak swipe, but don't expect it to make you invincible, champ.
Add 1 to min defense and 3 to max defense, lower speed by 2.
(Alternatively: divide endurance by 4, add to defense values. Depends on how much one wants stats to play an influence.)
Cost: 5 bucks.
Heavy armor: A good set of plate will stop those demons cold. Too bad you can't touch or see your own toes anymore though.
Add 2 to minimal defense and 4 to max defense, but lowers speed by 5.
(Alternatively: divide endurance by 2, add to defense values.)
Cost: 8 cabbages.
Daggers: Pair of knives. You stab with them. Preferably not teammates.
Divide speed by 2, add to attack roll.
Cost: 3 dimes.
Bow and arrow: Poking things with pointy sticks from the comfort of being behind your squishy teammates.
Divide speed by 4, add to attack roll. Uses ammo (arrows), ranged.
Cost: 4 greenbacks for bow, 1 nickel for 3 standard arrows, 1 quarter for 1 'splosive arrow.
Longsword: This is a sword. It is long.
Divide speed by 5, add to attack roll, and gives another flat +2 to attack.
Cost: 5 grand.
Enchanted Longsword: This is a sword. It is long, and screams with the souls of the damned. Bring earplugs.
Divide speed by 5 and magical affinity by 3 and add to attack roll., and gives another flat +1 to attack.
Cost: 9 grand.
Doombox: a boombox playing sweet tunes that lift the soul and raise your spirits. Demons hate that.
Choice of two tapes, more can be bought later:
Pounding techno music: Get your allies pumped up! Gives a +2 to all allied attack rolls.
Cost: your eardrums.
Freestyle jazz: Not even demons from hell can stand such cacophony. -4 to all demon defense values, -1 for allied defense.
Cost: Your sanity.
Do remember that a lot of the bookkeeping would only need to be done once, and can then be put on the wiki or whatever so as to minimize the math pw needs to do for a turn.
Gaggle of beakdogs
Attack: 5
minimal defense:2
Maximal defense:8
Dogs mutated to have large sharp beaks for poking. Low durability (hence low min defense) but comes in packs (so high max defense, to represent there being a bunch of them)
Dancing mantis
Attack: 6
minimal defense:5
Maximal defense:7
speed: 9
An extremely agile being that bobs and weaves around attacks, trying to get into a foe's blind spot to strike. Difficult to hit (hence high min defense), but also fragile (max defense is barely higher, so the moment you do get a hit in it's almost certainly dead).
For every point of speed that you are lower than it, lower min defense by 1. AoE attacks get +3 to attack value against this foe.
Hedgehog surprise
Attack: 7
minimal defense:1
Maximal defense:2
When it sense danger, ot bulges up and explodes into a spray of deadly rust shrapnel. However, if you spot it quickly, it is easily dispatched.
negates any speed or dex bonuses to defense (to represent the fact that AoE is good vs low armor high dex types).
Roll 1d4 + magical affinity level, you spot it if you reach at least 5.
Also, you can have as much or as little dice influence as you want. For example, the dancing mantis attack value of 6 could easily be replaced by '1d6 + 2' to make things less predictable. Oh, and if you keep the 'stats' of the monsters hidden, you could have a rather deterministic system (for the gm) but where players can't precisely predict how much power they'll need to defeat something when they first encounter it, but over time they'll learn and be better able to deal with known enemies. For example, if you don't tell the players they take a hit on defense value when they're much slower than it, they'll have to figure that out by themselves by carefully reading the combat description (which would then need to actually reflect things like this, of course).
The system is a bit like the munchkin card game, which is easy to use but has the disadvantage that you need to do some basic arithmetic, which is only really annoying if you don't keep a quick sheet to easily keep track of the numbers (recalculating everything every time can be a drag, but with good bookkeeping support that should be very doable). You could replace the two defense values by just 1 defense value, or even just determine combat outcome by comparing a single 'combat power' number, highest wins, and difference between the two decide who wins and what the outcome is (a kill, a draw, or wounding so tnat its combat power drops, making a kill more likely next turn). The exact mechanics can be as simple or complicated as pw feels he can handle, but the base idea of just rolling up a lot of variables into a few/a single number(s) that are compared stays the same.