Obviously they are different chemicals.
In soda because its acidic, sucrose breaks apart to fructose and glucose.
Yes: the two sweeteners have exactly the same metabolic impact. There is no health advantage to sucrose over high-fructose corn syrup. Even outside of soda, your body is extremely efficient at breaking up sucrose; it happens within some number of seconds when your small intestine enzymes hit it. There's a folkloric belief that the sucrose bond gives your body time to more slowly metabolize the fructose; it does not.
I don’t think they are chemically identical because at a minimum I’ve seen the result of freeze drying solutions of both and HFCS is liquid at STP while sucrose is solid.
So if you’re going to make the argument that they are metabolically identical then go for it but be honest about what you are saying. They may be chemically similar, but so is cellulose.