Why are robbers so tough!

[Krzych]

The economy in the RW2 is reflection of economy in the real world... sigh ...
the more money you have, the more money you can earn..

Taken this into account you should carefully choose your battles, and maybe at the beginning focus on trade, to build up substantial amount of cash.. because easily you could achieve Pyrrhic victory, after which you couldn't replenish your forces.. (like our friend He111).
This is especially due with Knight units (Pikemen are not cheap at the beginning also! ), because dozen knight warriors could cost you few thousands...
it forces to keep an eye for Knights in battle, and even using them only to chase routing troops, and not engage into fight in minor battles...