For EIB the overlapping method is acceptable. However, I STRONGLY recommend using the coverstrip method. It's easy to do, more accurate, and for some reason it looks WAYYYY better IMHO. You only do your build once. Do it the right way the first time so you won't regret it later. Also, even if you don't build it to Centurion standards right away, you will always be ready to do so in the future. A few things here and there are much better than having to pull apart all your armor pieces down the road.
Even if you are going for only 501st acceptance, I still say go with the coverstrips. You won't be sorry.
BTW I was formerly with the 4th Florida Infantry Co. G, and later, the 97th Pennsylvania Fife and Drum Corps Co. A. Not into reenacting anymore, now living in Japan, but nice to see a fellow living historian.