I am not sure that Brighton was Unitd biggest lose, but you have to understand that United played that game with 16 years old players, 40 years old players, and many people who never hit the ball before. You can't put that information as back than the professional players were in the war, and sometimes games played day after day and even in some cases two games of United were played at the same day with 11 diffrent players in each stadium. I will give you an example to today, same as back than when during games players from diffrent teams could play at any team they wished for (wartime guest players and few more names). see the game last season against Juve which United lost 1-2 to Juve, but the game involved 6 of United former players, which played that game as a testimonial match for Gary Neville, Yes it was United game, But as it wasn't competetive it shouldn't be added to the team record books (no matter the score line, even if they would ended up winning 20-0 or lost at that score).   –