Matchmaking
1:1 matchmaking is an insolvable problem. Devs target “good enough”.
But you could make some changes to war.
Changes
You could add some buffers to spread out some of the concentrations of imbalance that make matchmaking even more difficult than a 1:1 restriction.
6 attack teams AND 6 defense team
This would buffer the problems with revive, HotM defense, and the ( Fabian* strategy for war )
Wars last for 6 days
This would buffer the RNG problem. Everything except war energy, and points, resets every 24 hous.
Sacrifice play
Every 24 hours you can donate 1 war energy to any teammate. Removing 1 from your war energy bar and giving them an additional 1 war energy. Maximum +3 war energy per 24 hours. This would buffer the uneven teammate roster problem.
Wanted Hero Mission Chest
Each killed hero in war counts for the Wanted Hero Mission Chest. This would buffer the war loot problem.
World Energy
Every attack in war, rewards +3 world/ map energy. This would buffer all the above problems.
“Good enough”
But the Devs have moved on. They have a ton of other stuff to work on before they can get to trade which is a huge deal now that Pokémon GO broke the road block to effective MMO trading.