On the numbers...
Madina has gained 14 nobles from its "trough." Aurvandil has gained 9. That's an advantage to Madina... but it's not like Aurvandil is getting weaker. Both Aurvandil and Madina gained from Caerwyn's demise: Madina more maybe, but it might not be enough to tip the scales.
In CS, Madina bottomed at about 6400, Aurvandil at 2200... but they are currently both at 12000 CS. Pretty evenly matched.
While Madina has a big advantage in absolute food productivity, it's about equal in terms of ability to feed its population: both run big surpluses. Madina's better connection to foreign markets and larger surplus could be very useful for it... but I imagine the Duke of Paisly might find some willing sellers in the lords of Aurvandil, if they were personally contacted... maybe.
In terms of total income, Madina has a big advantage: but Aurvandil is catching up. Madina's new nobles will allow it to expand its income, but so will Aurvandil's. Madina's regions mostly have good population and infrastructure: Aurvandil is still developing. They have room for growth without expansion. While Madina certainly has more long-term growth potential, it will be a very long time before that equates to more military power, whereas Aurvandil's growth can translate into more military power pretty quickly. Plus, Aurvandil has demonstrated a better ability to leverage its wealth to full effectiveness (albeit with dubious ethics according to many reports). So they may not need to have equal income if they can manage it better (or maintain a defensive advantage on the walls). Then, for income per character, they're about even, though Aurvandil seems likely to rise as regions develop, and Madina seems likely to rise, but more slowly, as they expand.
In sum: Madina has gained something of an upper hand. But it's hardly over.
