Actually, I used the Niners last season and though the 3-4 is flawed in Madden you can get QB pressure by using some line and 'backer adjustments...
Seems to throw the O-line blocking schemes off...
QB pressure for me works best when adjusting the line so one of the DE's is playing well off the line and you bring a DB blitz...
For instance...
The CPU lines up with 3 wide...instead of a nickle package I use a dime DB blitz and adjust the line so that the LDE is off the tackle...then I control the RDT and do some rips or swims while I commit to the pass with the right stick...
Also putting a LB at the RE position in the dime is effective...
'Skins used to do it w/ Arrington...
That double wide suggestion in 3-3-5 and dime works pretty good too...
I'm also moving my #1 corner around and that helps too...
Putting him in the slot when I go double wide or moving him to the x and then doubling the z is effective...