Here is a replacement (totalconversion) ShipClassDefs.XML file, compatible with 1.03, which makes medium missile ships available: https://dl.dropboxusercontent.com/u/45479330/GC3/GalCiv3%20Ranger%20PatchMod/000_MediumMissileBoatFix.rar 

Here is a replacement (totalconversion) ComponentClassDefs.XML file, compatible with 1.03, which makes the missing 2/3 of enhanced ship designs available: https://dl.dropboxusercontent.com/u/45479330/GC3/GalCiv3%20Ranger%20PatchMod/000_WeaponAugmentFix.rar 

Place the contents of both into your :\My Documents\My Games\GalCiv3\Mods folder

There is currently an issue in ShipClassDefs.xml where every single 'ranger' type ship mistakenly pointing to the Destroyer class blueprints, which are large ships.

This means you don't get a medium missile ship when you've researched medium ships and missiles, nor does the AI have the ability to build them.

Instead, you get your Ranger when you research Large hull sizes:

Further, every BattleshipD points to the blueprint of a DestroyerD:

This mod fixes those issues, but changes nothing else.

In a similar manner, the AI's ship designer functionality skips over a lot of Augmented ships - that is, those which use Durantium, Elerium and and Anti-matter. It's especially limited in its ability to use Durantium. That's what the second file fixes.