As your dictionary allows, "equal" can have different meanings. For example, "value." Right now, one USD might equal 0.9 Euros. Does that mean that the dollar is greater than the Euro? Obviously not. Would $100 be greater than €90? No, they are equal. But are they the same? Obviously not. Sameness and equality are separate entities.
Adam and Eve were NOT equal in height, in their manner of creation, in their time of creation, in appearance, in abilities, etc. Yet they were equal in value, in position, in opportunities, etc. Unfortunately, sin extended the inequalities.