I think you would be better off to drop one day of something-3 days of lifting and 3 days of cardio or 4 days of lifting and 2 days of cardio orrr...3 days of lifting, 2 days of cardio, and 1 day of GPP.
Generally when people refer to strength, we think of maximal strength and this is often induced by lifting 85-100% of our 1RM for high sets (6-10), low reps (1-4), and at maximal levels.
If you're truly interesting in working on strength, then use less cardio and spend more time in the weight room.