Wanted to take it upon myself to point out this issue for Steam users as well.
For those who are using the KingdomsAppLauncher, and are receiving the "File 'kingdoms.exe' cannot be identified / found" as an error in a dialog box, or something along those lines when trying to launch from MTW's Kingdoms Launcher, try switching the KingdomsAppLauncher settings for Hyrule: Total War from Kingdoms to Medieval II.
For some reason (and this makes sense to me), kingdoms.exe was not included anywhere in my Steam version of Medieval II. KingdomsAppLauncher uses the default and launches Hyrule correctly if your mod is named correctly and your Configuration.cfg is selected properly when you switch over to Medieval II.
Thanks.
As a side note: as of 7/23/2014, I'm still crashing when going to select my faction. The best way to avoid this issue is to, instead, use Hyrule: Total War's wiki, scan through all of the factions, then quickly find which one you'd like to play and continue.