4-1-4-1 is not 4-4-2 with a sweeper/DMC because DMC is not sweeper. Sweeper would fit in 1-4-4-1 with the sweeper playing lowest of defense not midfield. 4-1-4-1 is also not 4-5-1 they are similar but not the same. It's not popular in real life only used for defensive teams with lower quality. Teams like Liverpool, Chelsea or arsenal play 4-5-1 but all different formation. Arsenal more like 4-3-2-1 with cazorla as AMC and Walcott as amr. Liverpool is more like 4-2-3-1 and Chelsea is like 4-5-1 V.