I don't find it ridiculous at all. His massive scale of jutsu is way out of a high jounin-low kage tier's league, number one (Has one of the biggest chakra reserves in the manga). He was deemed commander of over 10,000+ ninjas in the shinobi alliance which speaks volumes about his intelligence and leadership. Not only that, but he was the commander of the short-ranged battle division, which means he has to be very skilled in CQC despite his lack of feats; and we already know his long-range jutsu is on a top-tier kage and above level. So by hype in addition to his very limited, yet impressive feats, I don't find it far-fetched at all to say he is slightly above low-kage tier.