Yes that is true, the arch must be practiced !!!
I do that. It just seems different somehow when you have about a 30 lb chute on your back and have to arch hard into the relative wind. I am just a basic beginner and haven't pulled it all together yet. My jumps are also inconsistant doing some different stupid thing each time, although 5 out of 7 jumps, I was facing the wind and watching the plane. I do get plenty of help at the dz and get told what I did wrong. It seems a matter of getting the brain in gear with the body at the time of exit. It really doesn't look too hard. Hopefully it will
before the 100th Iad. ha ha