I don’t think you HAVE shown that the Hebrew word means “impute” in the theological sense of the word.
According to the Oxford Dictionary, in theology, “to impute” is to “ascribe (righteousness, guilt, etc.) to someone by virtue of a similar quality in another.” Then it provides this example ‘Christ’s righteousness has been imputed to us.’
I haven’t studied Hebrew, but the Septuagint translation of Hebrew into Greek (several centuries before Christ) used the same Greek word to translate “chashab” as Paul used, namely “λογιζομαι.” (logizomai) This word usually means “to count,” or “to number,” or “to consider,” or “to regard,” but never “to impute” (in the theological sense). Perhaps the best way to understand the meaning of a word is to see how it is used in many contexts. Please consider the following passages from the NKJV. The NKJV uses several different words to translate “λογιζομαι” but you will notice that for the past tense “counted” or “numbered” or “regarded” or “considered” fits most of them. Try substituting “imputed” in the theological sense of the word. How many of them make sense with that substitution? (I have reddened the NKJV translation of the word).
Mark 15:28 So the Scripture was fulfilled which says, “And He was numbered (“λογιζομαι”) with the transgressors.”
Acts 19:27 “So not only is this trade of ours in danger of falling into disrepute, but also the temple of the great goddess Diana may be despised “λογιζομαι” and her magnificence destroyed, whom all Asia and the world worship.”
Romans 2:3 And do you think (“λογιζομαι”) this, O man, you who judge those practicing such things, and doing the same, that you will escape the judgment of God?
Romans 2:26 Therefore, if an uncircumcised man keeps the righteous requirements of the law, will not his uncircumcision be counted (“λογιζομαι”) as circumcision?
Romans 3:28 Therefore we conclude (“λογιζομαι”)that a man is justified by faith apart from the deeds of the law.
Romans 4:4 Now to him who works, the wages are not counted (“λογιζομαι”) as grace but as debt.
Romans 6:11 Likewise you also, reckon (“λογιζομαι”) yourselves to be dead indeed to sin, but alive to God in Christ Jesus our Lord.
Romans 8:18 For I consider <3049> that the sufferings of this present time are not worthy to be compared with the glory which shall be revealed in us.
Romans 8:36 As it is written: “For Your sake we are killed all day long; We are accounted (“λογιζομαι”) as sheep for the slaughter.”
Romans 9:8 That is, those who are the children of the flesh, these are not the children of God; but the children of the promise are counted (“λογιζομαι”) as the seed.
2 Corinthians 10:11 Let such a person consider (“λογιζομαι”) this, that what we are in word by letters when we are absent, such we will also be in deed when we are present.
2 Corinthians 11:5 For I consider (“λογιζομαι”) that I am not at all inferior to the most eminent apostles.