I have been guilty of overpacking myself. But all of the above are excessive especially Norm's list. I also have two boys. Norm says 2 swimsuits for a 7 night cruise. We pack 7 each. One for each day. This is daily wear. (no offense)
We arrive to the ship in swimsuits, flip flops and tshirts. This is daily wear regardless of on or off ship The eliminates the need for underwear.
We dress for dinner. They can wear the same pants two or three times with different shirts. I do bring a couple suits. One pair of shoes for each is plenty in addition to the flip flops.
Now there is one area where I do sometimes overpack....