I am reading the rules of Risk, and at the top of the second column (in
3. Exchanging Territory Cards) it says that "if you hold 5 or more cards, you MUST exchange one or more sets on your turn". A "set" has been explained to be 3 cards with the same insignia, where a wild card can be used as any of the 3 insignias.
If for example I had these 5 cards - Infantry, Infantry, Artillery, Artilley, Cavalry - then I do not have a set of any insignias, but am forced to swap a set as I have 5 cards. The same could occur if I had 6 cards, 2 of each insignia and no wild cards.
Where am I going wrong in understanding this?