Now my thoughts as cities are named in order of citizenship, I suggest that workers are reverse order of player joining ...
Also from the perspective of information leaking and control ... I would suggest that a straight numbering system reveals too much about our military strength
As to who names military units ??? ... don't know ... but like the idea of leaning towards a unique naming system ... but not too complicated ... I would adapt Ram's approach but exclude class as this is a doubling up ie.
Hermes - Warrior - XXX and there is only a certain amount of text space available.
All ships should have a unique name and have an official naming ceremony (which the media is invited to) ... as to who names it ??? ... again I don't know but every citizen should have a turn ... or submit names to a vote ... however prior to whatever system for naming rights is initiated for ships ...

... I respectfully ask the populous to allow me the honour of naming the first ship ... I have it in mind to make it a dedication to one of the longest (started on 22nd May 2004) and talented and interesting Civ-based stories ever to bless this forum ...
Pax Romana by Vanadorn ... I would like to call our first vessel
The Snarling Narwhal ... see post 1506 on page 76
EDIT - Reason for stating new thread is that it was titled
Cities
and
All units will have to have the unit class in the name ... this is to not give false information with stealth attack and stack viewing ...