User blog comment:IamJakuhoRaikoben/Chapter 412: Dance Unto Ishgar, Review./@comment-1776824-20141208183425/@comment-9595671-20141208185944

That is true, but that last one also works in favor of them faking their deaths. If they were buried then they easily could have gotten out of their graves later (Dragons are powerful, I bet they could hold their breath for a long time) and then refilled them afterwords before they then hid in their sons like the other Dragons, so if Sting and Rogue came back to mourn they'd never realize their dragons weren't in the graves.