Here's my "groups" for the Weapon Training feat.
Weapon Training (General)
You’re trained in the proper use of a class of weapons. Heroes suffer a −4 penalty on attack rolls with weapons in which they have not been trained. When you select this feat, it applies to one of the following categories.
• Axes: battleaxe, greataxe, handaxe, pick (heavy), pick (light)
• Blades: dagger, greatsword, kukri, longsword, rapier, scimitar, scythe, sickle, sword (short)
• Bows: longbow, shortbow
• Clubs: club, flail, flail (heavy), greatclub, hammer (light), mace (light), mace (heavy), morningstar, quarterstaff, shield bash, warhammer
• Crossbows: crossbow (heavy), crossbow (light)
• Gunnery: artillery, cannons, vehicle weaponry (Modern, Sci-Fi)
• Heavy Weapons: machine gun
• Longarms: rifle, shotgun, submachinegun (Modern, Sci-Fi)
• Polearms: lance, longspear, shortspear, spear, trident
• Sidearms: pistol (Modern, Sci-Fi)
• Thrown: axe (throwing), dagger, dart, javelin, sling