Heres some things to think about when developing a leg program. First of all, how long does it take for you to recover. I think that people do one of two things. Either they train them too hard with long workouts or over do it to the point of not being able to walk or they don't train hard enough. So before you decide that you need to do a 2 day leg split, I would look at how you train. If a muscle is weak, the next thing I will consider is what the contractions are like in those weaker muscles. In order to grow, you have to be able to contract a muscle with such a strong mental connection. Hams are often weaker on people. Just like back, you cant see these muscles with your eyes. When you can see a muscle, say a bicep for example, its easier to get a good contraction from it but hamstrings and back take special mental connection. Its almost as though you have to be able to visualize those muscles as you contract them against the resistance of the weights. Then legs look at specific exercises. People often do squats like a power lifter. By doing this you distribute the tension through more of your body. Your hips tend to take more of the focus of the weight. You need to do squats in a way that will target the quad. So my point is, there are so many ways you can bring up your legs without changing your split. I meet very experienced competitors that want to get better and even they lack a lot of the things I brought up here.