That is because the standing in the groups A, B, C and D are not used to set the groups E and F, the team positions A1, A2 are on the basis of the lot no which was decided for each team in the group. Only if a 3rd placed team qualifies over the other 2 teams, that team gets the number of the team which it replaces (as in Group C, Team C1 was Australia, Team C2 was Sri Lanka and Team C3 was West Indies. Since Australia did not qualify, West Indies becomes C1 since it replaces Australia and not Sri Lanka.
