The Famous Men of Greece recommended in the Joshua through Malachi & Ancient Greece handbook was originally written by Haaren and Poland, but then edited by Rob Shearer. I’m not sure how much editing he has done, so I’m afraid I can’t describe the differences between the two versions. I’ve noticed chapter numbers and “parts” added that were not in the original, but I don’t know what else Rob added or changed. I tried to give the chapter titles, as well as chapter numbers, in the lesson plans so those using a different version would be able to match things up more easily.
So short answer: I would think you could use the other version if you want to.