The Riders are the only class with cavalery but they got no spearmen.
The Rangers and the Bounty Hunters got the same units but start with different upgrades.
I recommend to play and unlock all three castle wings for your archers and then loose till you start all over. You will keep your castle wings but loose everything else.
Then focus on the gold per kill upgrade.
I recommend not choosing archers - since bountyhunters start with the first gold per kill upgrade or the riders for their different units.
I have updated the game, its easier now. Also, you dont need to lose to win, it wont help that much. Just use powers efficiently, specially freeze when your units are hitting enemies. Use it once more when its regenerated. I hope that helps.
Thanks for your feedback, we have taken this into consideration.