TD, I'm not sure that the issues you raise would be anything new if the organization made the doctrinal changes I suggested. The "third class" already exists, since many members of the other sheep have died during the Christian era, even if we accept the old position that the heavenly calling ended in 1935 or the newer understanding that the date is indeterminate. Many JW's who died in the concentration camps did in fact profess to be of the other sheep, so the conundrum you suggest already exists, regardless of any future change in understanding - how were those faithful JW's any better off than non-JW's?
The answer from the JW's, as I understand it, is that even though both groups will be raised to earthly life, the faithful JW will have a big head start over the non-believer in having already accepted the "truth" and will therefore be raised much further along the road to eternal life. The unbeliever has a far greater chance of rejecting the "truth" and ultimately being consigned to the second death.