As I am the one that usually pushes the search button, I had experimented A LOT with our roster. My observations:
a. If you sandbag in a hardcore fashion, say 5 irons + 15 high level players, then chances are you will get another alliance just like you. War matchup will be hard.
b. If you don't sandbag at all, then prepare for another difficult war cause the others will have a few low level players and you will end up stronger at the end of your line up, but in the middle to high level numbers, they will outmatch you.
c. Recruit or create 2-3 accounts below 100 level (we have 2 accounts in Enlightenment age level 86 and 91). Have them always join your wars and also add a single iron age. I have concluded that this line up works best in WW and allows for fair matches without destroying your or them chances of winning. The results are based on matchups that took place the last 6 months. We had many unequal WW but most of them were decent and in the last 25 wars we have lost only 3.