Jack and Ralph are similar to Cain and Able Jack could be compared to tler because he is a dictator. Roger could then be considered Dr. Mengele, who was tler's worker I think it is a mistake to look for any exact, one-to-one correspondence with historical figures. Jack is a nasty bully boy and revels in savagery, but there is no need for a 'Godwin The novel is not an allegory where A1 in the story equals A2 in history.
For example, Simon as Jesus just doesn't fit. Ralph as Winston Churchill doesn't work, either; and why single out Mengele rather than, say for Roger? ( Many people worked for I think you'll understand the better novel if you don't search for one-to-one equivalents.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.