To answer the question asked, yes, these will “out the same data”. Anyone telling you they’re not the same isn’t looking at what you care about being the same - the rows output (regardless of order). From that perspective, and disregarding performance (as you also mentioned in your question) these queries will give you the same results.
I feel like this could really pivot on the glasses/containers involved. You’d need to know the volume of ice that fits in each before blending/serving and then reverse engineer the amount of “alcohol” (more like liquid generally, but with the assumption of same liquid concentration that doesn’t matter) that fit in the serving vessel at the end. But I’m Bobby Tables, not Bobby Mather.
The UNION removing any dups here is what makes them the same - the top query would never have duplicates as written.