One, you must give up the idea of each workout being some huge magic mushroom that's going to make you big. It's all about progression. This routine is primarily about strength then mass. The strength will pay off bigtime. How much mass you get depends on the individual but if you eat enough it should be very good.
So yes it's ok if you're able to do more. The idea of beating your muscles to shit thinking that's the only way they will grow is shortsigted. There will come that time again when the reps come hard on this and and when you plateau. There will also come a time when you are not really able to progress this way anymore at all. Starting light and building on it ensures that that time will be longer in coming. More progression equals more gains. It's a simple as that. You're squatting three times a week, after all. So yeah, I'm confident
