Answer
Nacional is the most successful club in Uruguay if Peñarol and CURCC are considered separate entities. Peñarol claims 50 domestic league titles, while CURCC claims 6. However, the two clubs merged in 1913 to form Peñarol, and the Uruguayan Football Association recognizes Peñarol as the successor to both clubs. Therefore, if Peñarol and CURCC are considered the same club, they have a combined 56 league titles, more than Nacional's 49.