Distributed acoustic sensing (DAS) measurements may be acquired at an observation wellbore during a current stage of a stimulation treatment along a treatment wellbore within a reservoir formation. A cumulative strain trace for the current stage of the stimulation treatment may be determined based on the DAS measurements. Based on the cumulative strain trace, whether or not to adjust a spacing of perforation clusters and/or a stage length used at the treatment wellbore for a subsequent stage of the stimulation treatment may be determined. Responsive to determining to adjust the spacing of the perforation dusters or to adjust the stage length, at least one treatment parameter for the subsequent stage may be adjusted. The subsequent stage may be performed based on the adjusted at least one treatment parameter.