Ma Atlantis is not dependent on its capital. The capital only mage sucks, W3 S2, because kings of the deep (recruitable anywhere) can get W3 S2 as well, plus 3xhps and 10% chance of another magic path!
Some races are just messed up
Ma Atlantis is pretty weak anyway so a boost to its capital only mage would be good, even if that increased the 180gps cost. Say additional 100% chance of WSDN for 240 gps cost?