Having rushed the first few missions to get gold rating got stuck on the seize derenhalle mission where you also have to kill the king and had to resort to cheating gold for buying troops as the remaining troop composition was simply put awful. Also could not get the relic as dont know the condition for it, at the moment any orc troop stepped into radius of church cinematic enters where the chieftain let it burn.

Once that had been passed came the final nail in the coffin(at least for me) in the form of the next level in the campaign, where you are to face off against an large human army led by both an sergeant and mounted general, an wall of range backed spearmen at the northeast and knights coming from the northwest.
At that point i simply gave up, because whats the point of playing if will have to use cheat in every mission.
The human campaign i had found to be awesome, passed without requiring any cheating at all, and the game seemed promising, yet the difficulty spiked immensely during the orc campaign as due to the way the game has been setup you cant employ horde tactics against the enemy such as swamping them with weaker troops to wear them down as so the veterans move in and get the kill, despite playing the supposedly horde faction. Frustrating as during the human campaign this was exactly the ai horde did against you, yet you are not allowed to do it when in charge.

As spears are good against cavalry i suppose you must build an sizeable force of goblins in the previous levels to be used as an wall against the knight horde charging in this level. The dilemma is that those are otherwise useless so there is not much chance you would have required amount of them upon meeting this tomato suprise.
Also rushing for gold completion in missions seems to be simply not worth it as the bonus gold you get does not pay for more than a couple more basic troops.

Oh I love that mission, I usually used some archers on the western hills and the hero with charge protection in the village against the knights, try to lure them with the balloon or some summoned unit. On the eastern side I have 3 or even 4 of those forester skirmishers, you know the ones that hide, scouting type. With those you can harrass the massive enemy army there.
Between those carefully advance the artillery.
Played through the game probably 15 times by now, the gold rewards are sometimes quite ok, but not worth sacrificing troops for, unless you want the gold reward for pride purposes. Generally it is better (and more fun!) to fully explore the map, especially in the first few missions, because one level of experience is always worth more than almost any item.

Don't face knights with units that don't have charge protection!