Soldato
I'm on madcow now after SL. I think it is a good transition between them. Why do you want to mix them? Have you hit a long plateau on squats but not on the other lifts?
How long have you been on SL?
I'm honestly just struggling with energy after 5 heavy sets and madcow is more forgiving with building up to 1 heavy set and having a lighter session. I've dropped and built back up once, today I'll be attempting a new 5x5 personal best in squats.