normal.jsx

const Chart = props => (
  <div className={styles.container}>
    <VictoryChart domain={[0, 10]}>
    {
      props.data.driveTrains.map((data, i) => {
        return(
          <VictoryGroup color={data.color} key={i}>
            <VictoryLine data={data.gears} />
            <VictoryScatter labelComponent={<VictoryTooltip/>} data={data.gears} />
          </VictoryGroup>
        )
      })
    }
    </VictoryChart>
  </div>
);

nutty.jsx

const Chart = props => (
  <div className={styles.container}>
    <VictoryChart domain={[0, 10]}>
      <Map array={props.data.driveTrains} >
          <VictoryGroup color="color">{/* Automatically adds key={index} */}
            <VictoryLine data="gears" />{/* Equal to props.item["gears"] */}
            <VictoryScatter labelComponent={<VictoryTooltip/>} data="gears" />
          </VictoryGroup>
      </Map>
    </VictoryChart>
  </div>
);