For homeschooling, this allows me to let my daughter set the pace. She already knows several letters. She can incorporate the success of the letters she does know into the study of 2 or 3 new and unfamiliar ones per letter play session. When I noticed she was confusing K and X, we started discussing the shape of the two letters (which are similar). I also made the X meaningful to her because it is the first letter of the name of one of her very best friends. In a public or private classroom, this prevents you from holding several students who know half the alphabet back while you spend a week on the letter A.
We won't wait to start pre-reading skills for when E has mastered all letters of the alphabet. You might be surprised that your child is reading sight words in the time it would have taken you to do 26 weeks of Letter of the Week!