Why do phonics lists in the beginners levels have so few words?
Here is a picture of one of the phonics practice pages from Beginners 3.
The lists on these pages are quite short.
I learned this the hard way, through experimenting with lots of students over a lot of years.
Longer lists of words are fine for stronger students, but weaker students feel overwhelmed when looking at them.
Also, stronger students who can read all the words on a simple list are probably ready for simple texts instead of lists.
Use the short lists to help students master a new sound.
Once they have mastered that new sound, you can have them try longer lists of words, but they are probably going to be more motivated to reaad simple texts instead.