Emulating our heroes is very tempting, but can be very dangerous. Arnold was a machine, plain and simple. The Austrian Oak. His routine was specialized to how his body reacts best. Plus he was on massive amounts of gear (I don't buy the argument that pros in the 70's used light cycles .. bullshit, they were on excessive amounts, minus hgh).
Anyway, two-a-days are taxing; I did a similar routine over the summer and after two weeks I was sick of the gym. I sucked it up, and finished a 10 week cycle of it, with OK results. I could have gotten the same by doing 5 day/week, 1 bodypart/day. The key is to go into it slowly and gradually. If you're going all out in the first week, by week 3 you'll be dead. Let us know how it goes