After playing with ballista we came up with few ideas:
1. Changing range 1-1 or 2-2
2. Lowering Piercing/dice
3. Starts with 0 tokens, soldiers as a full action can load a token
4. Lower survivability (hp/armor)
5. Increase cost and level
6. Unique, rule update - can only use one before/after conjuration per action.
Choose one