I don't think that the identity_id has any bearing on the sorting what-so-ever. It's only there so that if the sorting by standard and name result in entries tied for a spot, then the identity ID is used as the tie-breaker. Odds that the identity_id are used to do the sorting? Very low I would think.
Why does the sorting make such a big deal to you? What problem are ou running into that makes you need to change the sort order?