Ok so you're admitting that "over" is a complete insertion in Col 1:15, then please tell me why you kept trying to use the translation "over all creation" specifically highlighting the word "over" and its usage as reasons why Jesus can't be the literal firstborn of creation?
"Over is an additional word to expres the meaning of the Greek grammar."
Thats why. The Greek grammar used here allows this reading and is frequently translated this way.
Since I can agree with you that the verse literally translated is "firstborn all creation", can you show me a single example in the bible where someone labelled as firstborn regarding a particular group where themselves are NOT in that group?