Patrick Willis and Prez defensive combination?

Since both can get their X-Factors activated in wondering how good of a combo these guys could be especially at causing fumbles and turnovers? I have Prez though he isn't powered up for his ability discounts and am thinking about getting Willis also and just having them be my Sub/Lb's and have Hendricks play up top. I run a legends TT but have been thinking about switching to a 49ers one soon so Willis would fit great. I don't know if there are any other players that get great defensive X-Factors already activated though im sure there are.