Don't know if you saw my other edit to my first post above.
I agree the long workaround doesn't really work for NE as it uses up licenses; up to you, either:
A) Maybe get
Bug 10456 - hide account alias in gal search for ZWC reopened...but it's from 4.0 and that RFE flipped sides a bunch
B) 5th RFE "
Hide aliases on to: field GAL auto complete if existing match for an account is found" would help get decent behavior when people don't manage the 'hide alias' attribute that's going to come out of
14919
-Since part of the problem is sometimes you want them to appear & sometimes you don't, see attached pics - which leads to:
C) Or just rally support for
Bug 14919 - hide aliases in GAL on a per-alias basis -just added my vote
D) An RFE for combining them into one drop down entry (showing one account per line with all the matching aliases on the same line) would be interesting/challenging...