Your Duncan’s are Fixed Axle yoyos so you will need to use string tension to make it more or less responsive.
Hold the string about 2 inches from the yoyo and let it dangle, spin the yoyo clockwise for a while.
Then wind the yoyo. Now you will have much higher string tension.
You can use the trick Sidewinder to adjust tension in the future when the throw gets unresponsive.