You can make two (or more) identical limbs in the exact same place by using the grid and moving the joints on top of each other after you have set up the bones and muscles. That lets you make bipeds and quadrupeds from side view where the hip joint is shared by both legs. For me, these tend to evolve faster than single leg variants, since only one leg has to find the right cycle to propel it forward, meanwhile the other can dangle around uselessly until it finds a motion that improves the overall gait. It's very hard to get a balanced cycle like human walking, but it will usually find various lopes and gallops pretty easily.