To be honest, the army seems a bit small for month 6. Are you sure you've maxed out at least both main heroes? It would be good to level up the secondary heroes as well... Ideally, you should be getting +12 dragons per week from your native castles and dwellings. Is the growth of your spiders maxed out? (It should be +16)
1) Were there any significant losses on the Knight or Orange Elf that you couldn't recover?
2) Have you completed the other quests for the components?
The army might be a bit small, but frankly, what difference does it make when 600 hounds one-shot 500 vampires, and 170 steeds with luck kill 57 dragons. And the demon's initiative is higher even with my two initiative rings, and my 350 liches with a unicorn bow only kill 12 archdemons. It seems like you need an army 12 times larger to win against them. 6000 vampires or 800 dragons. And that's just one week. Something strange is happening. Either I'm just unlucky, and the entire scale only has one demon, its attacks are all with luck, and I can't do anything about it.