You can get the best 11 players in the country. 5 Excellent batsmen, 5 best bowlers, a couple best all rounders. Best left-arm, right arm combinations. All the them very fit fielders and the best wicket keeper.
Still, if they can't function as a team, if they bring their own agendas into the field, if they don't make and follow a team strategy, if they fight for the batting or the bowling order, if they don't have that fight in them, if all of them think that they are the best leader, and if they are not managed well, they will lose to a minnow again.
A team is better off with a great teamwork of above average players, than with excellent players with bigger ego.
