@Millard Baker its not about security with transferring to other wallets, it's about coinbase not closing your account. To be secure you would have to transfer from coinbase then transfer again once in tor and use a dark tumbler to dark wallet then back to a normal wallet not tied to anything.
Android makes it easy with samurai app where it simulates a tumble enough to make it pretty much untraceable except to CIA and NSA.
Again it's all about not getting your coinbase account closed. The more you transfer the less chance of that. In the end security on the money end doesn't matter much since most have it sent in real name to their house which is the true weak link.