i use the cardinals and this has been a huge problem for me also and as i play on all-madden i was getting killed by having no pressure cause my secondary cant cover to start with
i actually found help in the prima guide of all places
if you want pressure do not use the line shift because it weakens one half of your line
use line spread on all blitz packages and above all have your fastest players on all blitz plays..im getting alot of pressure now and forcing turnovers as well
also rush the end oppisite where the te lines up..