A couple of specific ways to nerf war engineering
Just trying to come up with a few constructive ways on how to prevent unbalanced war matchups due to heavily engineered and even defenseless bases:
1. Allow players to activate war layouts that don't use all buildings (in particular defenses, other buildings or walls wouldn't hurt either). That way, all players could easily reduce their war weight on a "as needed" basis without being punished for buying buildings that Supercell made available. In fact, this would be a preferable solution as it would allow players to benefit from defenses they bought in their regular bases without suffering the negative effects in war. Moreover, it would also allow players who built a defenseless base legitimately (without bots) to keep it around as a trophy without granting them exclusive benefits in wars at the same time.
2. Allow players to sell buildings (again) so that everyone could easily create an "engineered" war base of their own without any downsides to their regular villages. Supercell already gave us the choice of using different layouts for war, now we could go one step further and give us the choice as to which of the village defenses we want to include in wars (and in our war weight). Let's be honest here, many defenseless bases are the result of farming bots that do auto-raids 24/7. Even now, Supercell has not made any real effort to ban botters so this trend is not likely to chance anytime soon so giving everyone the means to lower their war weight on demand would negate any advantages that botters, gemmers and hardcore engineers have.
3. Disallow bases with too much of a gap between offense and defense to participate in wars. Players with high level defense and low level offense would be useless in wars anyway and players with high level offense and low level defense would most likely mess up the matchmaking and result in an unbalanced war.
4. Adjust war matching algorithm to place more emphasis on offense. If one side has 10 TH10 attacks with max offense available while the other side only has 5 such TH10 attacks available, it's probably a mismatch. It shouldn't matter that 5 of those 10 TH10s could be defenseless bases sitting at the bottom of the war map below TH4s. Offense wins wars so it should be important factor in matchmaking in order to have a balanced war.
5. Only one attack per player per war. Right now, an engineered (defenseless) base can only give up 3 stars but he can make 6 stars himself. You do the math! Letting people only once would make them think twice about using a .5 or defenseless base in war. Another added benefit of this approach is that it would kill modding once and for all. (Any attack that a clan would have to do to find trap/tesla locations and determine CC contents would mean one more enemy base that remains unattacked.)
to be continued ...