So there are quite a few achievments that require your opponent to not surrender, so how about having a specific achievment battle option?

Now what would be special about this would be that there would be no surrender option, you have to finish the battle all the way to the end

Now that's not to say you can't get achievments in normal battles, but this would greatly help the people working on those long "opponent must not surrender" achievments

And before you say: "But maybe the mods want it that way" I can distinctly remember one of them saying (i think it was takeko) that they didn't want achievments being decided by your opponents, which it kind of is if you need them not to surrender

I kind of disagree.
It would be a waste of time, and doing it in a normal battle is what makes it fun.

Most of those battles would end up being from their wins. You will eventually win that achievements so it wouldn't prevent people from surrendering, and once they do get that achievement then there really is nothing stopping them again.

I think I better change would be this

No way. Use your skills to end it quickly before they surrender and ect ect.

Even when you can't surrender they will just close the ingame screen.