The thing I can see is that in multiplayer, we can SKIP a base we dont feel comfortable with... we cannot do that in war, saying, "Eh, this clan looks a little too strong, let's skip them."
Personally, I think that the clans matchmaking system, by and large is pretty accurate, and I have been extremely happy with how well I have been matched up with many clans thus far! However, the issues come in where there are Engineered bases/clans. Even .5 THs can make a huge difference if there are enough of them. My current clan mismatches probably more often than not, because we have 7+ .5 Town Hall levels... Sometimes it is out of our favor, and other times it is in our favor. Frankly, it is an issue that WE as the clan need to fix, not the matchmaking system needing to fix... and it is a risk we take every single war. Honestly though, I have enjoyed being matched against a clan with a sllight advantage, because Otherwise I get no challenge... haha.
Where .5 TownHall levels are a minor issue, I can easily live with the slight mismatch that is inevitable regardless of our clan having .5 townhall levels or not, the True menace we run into as a clan is a clan with engineed bases... We have only lost one war in the past 20+, and that was to a clan with 25 engineered bases and .5 townhall bases out of 40 members. Now THAT is rigging the system. We literally stood no chance at all to them, and the otherclan unfortunately didnt even attack well at all... With their th10 level attacks they still couldnt even close all of our th9 level bases...Their max th11 couldnt even close all of our th9.5 bases and the dude had max offenses... We honestly would have crushed the clan in a fair fight, but they had such an overwhelming number of engineered bases honestly stood no chance and failed by a very small range.
THE POINT OF MY LONG WINDED RANT:
... is that we need to fix Engineered bases, and I watched a Youtube video that explained it PERFECTLY. To sum up the video, he says that we need to adjust defensive weighting so that the absolute minimum weight a Town Hall can have sould be the absolute max weight of the former atown Hall level. That means that if your base has the red level 10 Town Hall on your base, the absolute minimum weight your base would carry would be that of of a 100% max Th9 base. And to extend on that idea a bit, I think I should throw in my own two cents on the idea in saying that it would cater exclusively to the defensive weight of the base and that an individual with rushed heroes or other offenses wouldn't be at a weight disadvantage. I hate to fight for the rushers, but it is inevitable that a very large percentage of the clash community is rushed offensively over defensively, but from a war perspective, these are also the guys that cannot attack very well regardless... It is no loss to the serious war clan community and I think those guys would be taking a big enough hit defensively, because many of those people might be going to the next townhall level without levelling up every single defense anyway.
Either way, the video explains everything a bit better than I perhaps have: Start at 4:10 for what I am talking about
https://m.youtube.com/watch?v=dqEDr3BHAjk