[Mobhack]

The long campaign chooses the opponent for you depending on theatre and year.

The generated campaign, you select (up to) 3 opponents. it is up to you to choose these and ensure they are in synch for the entire time frame. The generated campaign is really only of use for a single theatre and period. The only exception is in MBT, where if you choose Communist China in the period before the Yalu river, and have North Korea in the mix, then any early "Chicom" picks will morph to Norks. That allows a full USA/Allies Korean War LC.

So e3nsure the opponents match in date (e.g. One Spain vs the other, for a Spanish Civil War generated LC, no Germans or Italians, unless you choose the exact era those foreign expeditionary forces were in theatre).