you might as well wish for a 3-4 olb as well. neither are going to happen. while it certainly is a bit unconventional it seems evident to me that the type of player you desire does not fit what GW wants to do. obviously you can disagree with such a scheme, but im comfortable allowing GW to run the defense as he sees fit.
moreover, i dont think they really see their safeties as strictly box safeties. i believe they see them as being physical enough to play the run and fluid enough to play the pass (albeit favoring the run, perhaps a 60/40 split?)
in any event, did it work last year? while giving up a fair amount of yards, the rams ended up ranked 12th in scoring defense (with several key players sidelined). their is obviously room for improvement but its not like the scheme was an abject failure.