You evidently use the King James Version translation of Zechariah 12:10 to prove your claim that Jehovah God and Jesus Christ are one person. Could you prove this claim using more accurate modern Bible translations? Some of them are cited below.
“They will look at the one they stabbed to death.”- The Bible in Living English, Byington
“They will look at him they have pierced.”- Living Bible, Taylor
“They will look at the one whom they stabbed to death.”- Todays English
“They will look at the one whom they have pierced.”- The Jerusalem Bible
“They shall look on whom they have thrust through.”- New American Bible.
“They shall look on him whom they stabbed.”- Moffatt
“They shall look at him whom they have stabbed.”- American Translation, Goodspeed
“They shall look upon Him who they have pierced.”- Modern language Bible
“When they look on whom they have pierced.”- Revised Standard/New Revised Standard Version
“Their eyes will be turned to the one who was wounded.”- Bible in Basic English
“When they see the one they pierced with a spear.”- Contemporary English Bible
“They shall look upon HIM¹ Whom they pierced.”- The Complete Bible in Modern English, F. Fenton.
You seem to have missed the point. All of the statements that you quote from the various English versions of the Bible convey the same thought. The Roman soldiers thrust a spear into to the Savior’s side while He was on the cross. The key is that this verse is referring to the LORD, as is consistent with verses 6 and 7. Then verse 10 refers to him whom they have pierced, stabbed to death, thrust through and wounded, as the Father’s only Son, and as the Firstborn (the first born referring to the first born spirit of God the Father). These references refer specifically to the Savior, who is equated to the LORD, or in other words, to Jehovah.
Further, what makes you think that these later translations are more accurate than the King James Version? Indeed, they are not. You will find that in addition to couching the scriptures in modern English in an attempt to make them more understandable to the people of today, in many places they have altered the meanings of the more original translations. If you were interested in a comparative study of the accuracy of the King James Version compared to the Septuagint, the Latin Vulgate and the Masoretic Hebrew texts, you might peruse “The Legacy of the Brass Plates of Laban, A Comparison of Biblical and Book of Mormon Isaiah Texts,” by H. Clay Gorton, Horizon Publishers, 1994.