I never thought much about the Battle of the Seven Potters at the beginning of Harry Potter and the Deathly Hallows: Part 1 when watching it the first time. Now after rewatching, I'm wondering why The Order didn't use a double decoy instead...to make Harry change to another person while the rest changed to 7 Harrys. If they were so adamant to keep Harry alive, wouldn't this way be the safest since the Deatheaters would still have 1/7 of a chance to get to the real Harry?