No, you aren't the only one. But let's consider the following: to maintain a viable rotation, we need to have four DTs that can rotate without significant dropoff.
We have THREE -- and not just warm bodies, but three experienced, game tested, proven commodities who are all difference makers. That's a great starting point. We need at least one additional player to emerge. Harper is the most likely candidate, as a third year player. Don't know if SG will ever see the field, but maybe he can be the fifth guy. If not, there are several newcomers who might get into the mix.
I think it is likely that at least one player emerges from that group, and possibly more than one. And as mentioned by others above, the 4-game / not burning a redshirt situation will also help.
Being unproven is different than not having the chops. What seems like an issue now might not be if Harper, Grovs, Okechukwu, or one of the newbies is ready. I think it is far more likely that a player or two steps up than none of them do, and we're stuck with a three-player rotation the entire year.
I wish that the coaching staff had moved Elmore last year, and stuck with it. Would feel better if he was in the mix at DT.