In this commentary, we venture to explore the “unity in diversity” dilemma revolving around the tension between human diversity and standardizations as it appears in the context of SDG4 and in the intersections between inclusive education and educational assessments. Since inclusive education and various forms of assessment data are at the very heart of SDG4 (Fontdevila, 2021), our argument is that the tension between diversity and standardization permeates both domains, and that there are valuable lessons to be learnt for the future administration of SDG4 from the paradoxes arising between inclusive education and assessment. The commentary concludes that greater attention to “diversity” and the finding of meaningful contextual solutions in the roll-out of standards are needed in order to avoid SDG4 turning into a global governance tool that distorts representations of success and failure in education.