Magical Power by State
Magical strength in Aurelion is not the number of casters in uniform. It is ritual multiplied by place, price and discipline: the same state can dominate one kind of war and become mediocre a hundred miles away.
No One Wins Every War
The source opens its state-by-state magical estimate with a formula from Mezgrin: magical power is not a sum of wizards but a product of ritual, place, price and discipline. That sentence is more important than the ranking beneath it. Aurelion's institutions do not all compete in the same medium. Gildglade can turn city, altar and artifact network into a local reactor. The White Kings specialize in making other people's magic stop working. Three Coins can alter a campaign through contracts before armies meet. A storm fleet carries a theater of power with it so long as there is sea beneath the hull.
The Empire of the Black Sun has the highest listed offensive peak because its ritual system can mobilize mass sacrifice and fire-liturgical formations. The Dragon Bone Dynasty approaches that scale through a completely different logic: bone batteries, constructs, alchemical support and prophetic cycles. Both are formidable in direct magical war, but their costs are different. Black Sun consumes its own society in long campaigns; the eastern system depends on difficult material logistics. Cut the supply of bones, reagents and engineered support and the peak collapses.
Gildglade occupies the most deceptive position. Within the city and its near perimeter, gold and illusion interact with the Separation Node, artifact networks and ritual economy to create one of the strongest concentrated magical environments in the setting. Move that force away from its "nest" and much of the advantage disappears. The Federation has the same problem in another element: it is a major power on the sea and a much smaller story on land. Location is not a modifier added after power is calculated. Location is part of the calculation.
The White Kings demonstrate the final asymmetry. Their offensive magical peak is not the highest, yet their anti-magic can exceed it dramatically through White Flame and seals of sterility. They can win a magical confrontation by reducing the battlefield rather than filling it with larger effects. This is why the ranking should never be read as a league table. Black Sun wins the dirty magical assault; Dragon Bone wins engineered escalation; Gildglade wins at home; Three Coins wins the campaign contract; the White Kings win the right to ask whether anyone gets to cast at all.