I thought about that to...
Lower the reward mentioned at the start of the battle, and instead reward every 3 combination with some gold, every 4 with more, 5 with even more, etc. There already is a gold cap (100) on a battle, raise that default cap, and change the money making cards (like alchemist) to give more gold per combine.
That would make the gold more effort based, and not so much funky algorithm based.
Like I see 2 teams I can attack, no defense bonuses or anything, the one with 1 card and team score 4949 gives 813 gold, the one next to it with 4 cards and way higher team score 8217 gives 872 gold.
That doesn't sound right...
The guy on the right only gives 921 gold, but he is using a team with full 50% bonus cards...
Those cards with bonuses on them should be taken into the reward calculation. If they are 50% tougher, then also give me 50% more reward.
I think two things are at play here...
1: People set up good defense teams, that can really make a fight drag out for quite a while.
There is nothing wrong with that, but it does severely limit your gold making abilities.
If the effort to beat them was rewarded, this would be much less of a problem.
2: You kinda HAVE to do PvP if you want to make any gold and be useful to your guild.
Especially since PvP gives gold AND trophies.
I wish there was something you could do that would net you a nice amount of gold, besides PvP.
Treasure maps are fun, but in a way totally different, plus they don't give that much gold.
The arena idea is nice, but the number of available cards should be a lot higher, and I'm not even sure about the reward.
Some kind of challenge mode, where you take a team, and battle opponents increasing in strength and reward would be nice...