You said you give the players no choices. You are even currently arguing that choices don't exist in the game.
Spoiler: evidence
Reading Fail! In Timeline B you already kicked the bad players out and you are running their PCs (as NPCs) through the campaign. How would that story differ from Timeline A.
I am going to guess you would only allow the first two reasonable solutions and even then I expect you would pull a gotcha on the first. Everyone else here would accept most of these and some not listed.
- The characters attack and kill each other's clones (so none dies by their OWN hand)
- The characters attack but do not kill the clones
- The characters inform the clones that the clones souls will also be forfeit to the contract if they fight to the death. Thus they peacefully disengage
- The characters run away through dangerous terrain
- The characters run to some allies/enemies that can attack the clones without triggering the contract