Can a Sekirei wing another Sekirei, or is that limited to only Ashikabi?
It seems strange that what should have possibly saved their species was instead made to rely on any sapient native species on another planet. Or was that artificially engineered by the genetic tampering MBI did?
Can't say. But there is a fanfiction or two which mess with the Mechanics of it. Check out No Game for Old Men on fanfiction.net. 16 chapters or so with sub notes on the powers and winging progress. These are sadly not canon however.