Some basic misunderstandings between Thorp high-low count system and Basic strategy !

First of all, I will like to thank everybody who read this article. despite my bad english (which I apologize for) I hope you will understand what my point is and please feel free to comment on anything you would like to.

1. Basic strategy
Hit hard 12 versus dealers 2 and 3, and stand on hard 12 versus every other card.

2. basic index probability (high-low count, thorp Beat the dealer)
The probability of the index to be -1 and +1 is the same and so on for -2 and +2 . . . . .

3. Alright, so long so good!

Index chart: Dealer hold 2, you hold 12, stand if the index is greater than 12.

Now, lets go back to basic strategy, which say always hit, which makes sense since the index is more likely to be 12 or below then greater than 12.
The same goes for hitting on 12 versus 3, which say greater than 6. Same thing, as to probability.

Now, where I get confust is:
You have 12 against a dealers 4 =
basic strategy say stand !
high-low index: greater than 4 = stand.

Now, when index chart say hit when the index is not greater than 4 will it meen that I im suppost to hit more than I stand ( simply because of the posibility of the index being less than 5 than more than 5 or 5 )

same thing with 13 against dealer 2.

Why do basic strategy say stand when the high-low system say hit more than stand ? So as to probability, basic strategy should say hit on 13 against dealer 2 and hit 12 versus dealer 3 and 4. Or if basic strategy is right, than must the index chart be wrong or what ? what is the reason for these to systems to be misleading each other ?

I hope you understand my point of view and why I am confust.