Do you consider autocalc cheating? If not, then it's time to fight a war of attrition. Save your top, top tier troops like honor troops, but you can start attacking with everything else autocalc. You'll get massacred and take more losses than kills you inflict, but you should be able to get them down to manageable levels. If they only have one city left, you should be able to recruit faster than they can, especially if you've destroyed their economy and raided their villages. I've noticed that raided villages provide no recruits when I ask my squire to auto-recruit.
You will probably need more than a 1000 troops to inflict 300-400 losses on the enemy. You have a lot of money so it should be possible.
You will probably need more than a 1000 troops to inflict 300-400 losses on the enemy. You have a lot of money so it should be possible.