if you got something funny or any other reasons just post
It is funny that I have some easy counter-arguments for a lot of these points.
1. if the enemy is marching toward your capital
... you simply throw a stack of siege weapons at them and take advantage of your additional movement over home-territory Roads to throw the book at the enemy, decimating their stack and thus making a conquest of their territory relatively easy.
2. if you keep losing battles
... it means that you are likely fighting an AI and are winning a war. You won't consistently win without sustaining any losses. The only trick is to ensure that you win sufficient battles to take the City that you are trying to capture, no matter how many battles you lose in the fight over that City. Accomplishing this goal usually means bringing, at a minimum, more than twice the number of City defenders to the battle, and often more than that ratio.
3. if you just lost your great general
It happens. Sometimes you will lose your entire stack, along with the supposed-to-be last-to-defend Great General with it, but what's more important is whether you're focused enough on the war to be able to recruit enough units to make up for this unfortunate circumstance and can swing the momentum of victories back to your side.
4. if your best battlion was just sent packing
... simply create another one! If you are "cultivating" City Raider III (or whatever your best batallion units consist of), you'll have more in short order. These top troops don't exist to win every battle, but exist to help crack either the top defender in a City or else to break through a strong counter-unit, like a Maceman with City Raider III beating a troublesome defending Crossbowman. Even if your unit lost, it still likely served its purpose in damaging the defender sufficiently to make further fights easier for the rest of your army.
5.if you lost 2+ cities in one turn
This situation is a great way to win a Conquest Victory when your Land Area is large enough for you to otherwise be awarded a Domination Victory. I lost Cities in this manner recently in a Game of the Month game and still won the fastest Conquest Victory.
6. if you retreat in mass
... you will live to fight another day, I say!
7. if your enemy believes in total warfare so if you do get that ground back theres no point in keeping it
Gift a junky City that you build just for the purposes of ending the war, preferably one with few or no Resources in its fat cross. Make it close to your capital and preferably spread your State Religion to this City before giving it up as "war spoils." Then, send in Spy after Spy and wreak havoc on your now-at-Peace enemy!
8. if you are trying to capitate
I was trying to figure out how to capitulate my empire to an AI's empire in games where I was doing well... I just wanted to see if I could trick an AI into taking me on and giving me a ton of their Resources and techs... unfortunately, this potentially easy-to-exploit functionality of becoming an AI's vassal doesn't exist (maybe it does in a Mod???).
9.if youre realling on allies to fight your battles
Then you are playing a tactically-sound war. What good are your war allies if they don't engage in the fighting? Let them lose some of their power and then you can ride in at the last minute to claim the prizes (the enemy's Cities).
10.if you lose a 100.0 chance battle
Do you REALLY want to see the exact percentages showing up with 16 digits of precision or are you okay to accept that there is some rounding in the display? The only battles that are 100% guaranteed are the "free" wins against the first Barb units that you encounter on lower difficulty levels.