you are right when saying that "simply tried to expand their knowledge" is taking this a bit too far, the tree of knowledge being actually the tree of knowledge of good and evil and not of "knowledge" tout court
However it is a matter of fact that Christian literature is full of symbols such as sheppards, sheep , lambs etc
Ok,you can claim that a "sheep" stands for a peaceful animal in opposition to the wolf
I can not however but think at a sheep as an animal following the sheppard without asking questions