Electron plasma wakefield acceleration (PWFA) mechanism is a promising non conventional
acceleration scheme. Nonetheless further investigation is still needed to fully uncover
the instability mechanisms so to mitigate them and make PWFA an effective tool. This
work focuses in this direction, we discuss the necessity to use well matched driver bunches
to further mitigate witness instabilities. Specifically we propose to inject driver bunches
with larger emittance than the matched one (overcompressed bunch) so to let the system
reach the matching condition by itself. This preliminary results lead us to the following
consideration: while a limited number of cases can be studied with a particle-in-cell code,
we understand the necessity for fast systematic analysis: we briefly introduce the hybrid
code Architect
