What is Training and how can you counter it?

I'm all for the training system. Now, the discount system works like a loyalty program in a supermarket. You can easily train Knights (which I was doing anyway), while leaving the peasants to earn money. The only downside is that you now need a hero of at least level 4-5 stationed in the Castle (otherwise, you won't get the discounts), so you have to sacrifice the development of your main hero. It's especially a pity to lose experience points early in the game. However, the game has definitely become more interesting.