soft hand blackjack

Why is the deficit in the strategy blackjack cards?
I try to memorize a table for 4 + decks, dealer must hit Soft 17, and I realized that there are missing numbers in the letter. For example: Theres not one hand <8. I checked several charts and everyone seems to be the same.
For any changes to 8 or less, except for doubles, you will always succeed, no matter what the dealer did. Even if the dealer shows a 3, 4, 5 or 6 and you have a total of 8, you should always just click instead of double.
Strategies for Blackjack : Soft Hand Tips & Techniques for Blackjack