Start with the mounting geometry
Record the mounting height above the actual calculation plane, not only the nominal pole length. Brackets, foundations and site grade can change the installed geometry.
Compare the exact distribution
Fixture optics shape where light lands. Ask for the exact IES file and fixture orientation; a visually similar housing can contain a different optical system.
Test alternatives before selecting a count
Compare feasible positions and heights using the same project criteria. Document which changes improve the intended area and what happens at the boundary.
Coordinate physical suitability
Fixture weight, wind area, pole condition, foundations and electrical work belong in the construction review. A lighting calculation does not approve those conditions.