Agreed PvK.
That is what I also do; Copy the added Ship Set plus my favorite Speech file to that MODs new Race Folder.
If one wants to add additional Race Ship Sets to a Mod to play against, then you must add the AI as Fyron recommends also to follow Fyrons advise if one desires to drop out of a multiplayer so atleast some AI will continue in your absence.
Besure that this new AI has the existing play MODs AI General file, to insure any Char, Happiness, Design Name,Planet Type, Atmosphere, Culture and Trait changes will take effect 
For example with QB's AIC Eees AI to the FED. the Eees general file must be used as well as all others and renamed to FED_AI_General.txt etc. Other wise you may not have a Race or Home World that you would normally expect
This also would apply to interchanges with most mods, for example Proportions as well QB, if you wanted the Star Treks FED in a Proportions game you would use PvKs Eee AI to that new FED folder and besure to rename all. Other wise you may not have a Race or designs that you would normally expect.
[ October 30, 2003, 20:57: Message edited by: JLS ]