So I am stealing Happerys list and changing it a bit to how I see a gnome army >_< I wanted to see a mad scientist and I moved the flying unit and changed it a bit.
Clockwork units don't get xp and can only be healed by engineers.
Migrants:
As above
Tinkers:
As above
Hillguards:
As above
Steamguard:
Gnomes armed with steampowered repeatercrosbows. Able to fire a deadly hail of bolts at the enemy and when they get close they can mount bayonets and use the crosbows as spears. Only problem is that gnome sized spear and bolts deal very little damagde. If you enchant it it can become a really heavy hitter though.
Clockwork swordsman:
Slow swordman unit with low initiativ and low to hit. They have higher armor, more hp and hit harder than other swordsmen.
Clockwork Gunner:
The tier 2 shooting unit. Slow and heavly armored they use steampowered heavy crossbows to throw down some seriuce fire support.
Clockwork Gliders
Gnomes flying with clockwork gliders! They have no armor as that would be to heavy and no meele weapon. Instead the fight with speed and handrepeater crossbows. The idea is to give the gnomes a very early, but very weak flying unit. Good for scouting and taking out small armies with no fliers or ranged units, but they die as soon as they see any real opposition.
Clockwork tiger
As above
Illusionist
As above
Trickster
As above
Gnomish Spitfire
As above
Clockwork Dragon
As the clockwork dragon above. Just a tier under.
Brilliant Scientist
Top tier unit. Can build rail road/lighting roads/what ever you will call them. Works like roads. Just better.
In combat he have a large, but random arsenal of deathrays, freezerays, glue guns, bobbytraps and other crazy inventions.
He is also able to repair clockwork units and even improve upon them after combat. I had a complicated system in my mind for this ability, but then realised it would be much easier if he just enabled clockwork units to get xp.