For more information on the Calliope build and They Are Billions in general, be sure to check out the following resources:

Calliope is widely considered the "pro" choice for players who enjoy high-intensity micro-management. While she feels "weaker" early on due to low damage, her ability to outrun almost anything makes her the more efficient hero for repeat playthroughs. Do you need a specific mission-by-mission strategy for Calliope, or are you looking for the best Colony Tech Tree to support her?

Maxing range allows you to aggro enemies from a safer distance (ideally 6+ cells), which is critical because she cannot tank hits. Priority 2: Movement Speed