I'm not sure it is. The League Cup is generally won by really high level teams like Liverpool or Man City, and the final is played in March before those teams burnout or reprioritise based on League/Europe. Clubs like Woolwich, Leicester and Man United have all won the FA Cup recently, while the latter was an outlier in the League Cup last year. A lot of it comes down to luck of the draw too, I think we got City at the worst time this year early in the competition. Tbh, with City where they are you need a shit load of luck to win anything in this country these days.