You have to remember that there are always 3 swing highs and 3 swing lows. There is the last Swing High and Low on M5, on H1 and H4. Sometimes they are the same and sometimes they are all different on each of the 3 charts.
However, according to the 3 ducks method (eBook), the trade should be placed on the M5 chart and the swing points to focus on are the M5 ones and not the ones on the higher time-frames (Pages 10-13). It also mentions that you should close out the trade when it crosses the SMA60 again (Page 13).
Obviously, this is discretionary and traders can opt to use the swing points at the higher time-frames but do this if you are skilled and know what you are doing. This is because the position will then be a longer-term one in which the third duck is ignored during its duration (you will not close out on the M5 SMA crossing).
Personally, I believe that if you only use the swing points of the higher time-frames you will defeat the whole purpose of using the three time-frames since your trade will only be based on two or even just one of the time-frames. Obviously, this is not a problem if you are a skilled trader and know what you are doing, but if you are still trying to get your “duck hunting license”, it is best to stick to the M5 for the swing points.