How so? Is it a permanent boost to strength? If so, that could work, though it would be disadvantageous to lose any of those units since new ones wouldn't have it. If it's only temporary, then that's pretty much a weaker version of the Hippus worldspell.World Spell: Rise of the Halfmen, gives all halfing units extra strength
The arquballista is apparantly the repeating crossbow.
Edit: Ok. I played it. My Thieves kept getting mauled by spiders and gorillas and then Orthus spawned right next to my city and raped me. You may want to add a city defense bonus to the warriors.
Well, I really could use some ideas to make them more interesting
Saying they are boring isn't very constructive criticism.
I can manage to survive with them, it's a challenge but they are halflings- they aren't meant to be strong.
Sorry, brah. Didn't mean to be negative. I've been thinking about it a bit. Some of these ideas could be used, some not, and other completely proven unworkable.
1. They can steal a small amount of gold from an opposing city. Put some kind of limit on it like a 10 gold max and have it take a few turns. And if they fail, the unit is destroyed.
2. Give them a bonus in forests. I imagine they would be good at using forests to set up ambushes, hide, and other such things.
3. Give them a UU that gives +2 gold whenever they kill another unit. It could be a tier 2 or 3 unit.
4. Give them a UB that gives recon units extra experience. I imagine them being very recon-based, so they would focus a lot more on training their recon units than normal melee units.