By now I'm sure we've all had matches you could tell were heavily imbalanced, and as a clan decided whether to concede after seeing the opponent not only has a decisive theoretical advantage, as well as committing to the attacks and executing.
Since it's obvious that many wars will not be anywhere near equal, even months after matches generate data for the matching process, I'm sure many players would appreciate the option to have 2 (or more) layouts for fast switching.
No one layout can be good at everything, and trade offs to counter one strategy mean opening up weaknesses to another. This is fair game for making war battles (and regular) interesting. When it's not interesting is when you can see the war is lost before it starts. In these cases all you can do is to try and set up your base to not allow for "cheap" one star attacks for their cleanup players. Unfortunately, there is no simple or quick swap-able base you can design that caters both to your war design and one that is solely designed to prevent picking attacks (versus your normal design which usually tries to stop 2 and 3 star attacks).
If it's not bad enough that you go in knowing it's a loss, the idea of other players being able to easily profit off the bad matching is just as frustrating.
I would otherwise suggest a concede function, where the winner takes a reduced but automatic loot amount, but I'm sure this would not fly because I can see easy abuses of the system. My request then is the easiest alternative I can think of to mitigate the poor matches.
Yeah, we definitely need this multiple base layout save slots. I wonder why such a great feature is not yet implemented. It will add a lot of fun to so many players. Currently rearranging base layout takes too much time if you're really trying to make a good one and when you want to experiment it is very inconvinient.