I can’t figure out how it works out for the entire order, but I like the Maor vaShemesh’s answer at least with respect to explaining why “Di Zahav,” the cheit ha’eigel, comes at the end. I think there is a psychological truth to his answer, even though in pshat there may be better approaches. He suggests that had Moshe focussed on the cheit ha’eigel first, the conversation with Bnei Yisrael would have ended pretty quickly. The sin was so overwhelming that to even think about a tikun was outside the scope of what anyone could imagine. Therefore, Moshe left it for last. First, start by doing teshuvah for the “little” stuff –- “bamidbar, ba’aravah…” etc. Bite off what you can manage. Chew slowly and digest. Eventually, when the time is right and enough positive momentum has built up, the really big problems, the “Di Zahav,” can be addressed.
I was thinking of this idea on Tisha b’Av. To approach Tisha b’Av with the idea that, “OK, now let’s do teshuvah and we can rebuild the Beis haMikdash,” is not going to go anywhere. “Let’s abolish sinas chinam and lashin ha’ra” – it’s not going to work. It’s too overwhelming a task and bound to lead to frustration and failure. Moshe Rabeinu's tochacha teaches us that it's best to start small, with little things. Do what you can one step at a time. We'll get to the big things eventually, but it has to come as part of a gradual process.