Yes, the big ships here must be the "warp-capable ferries". The shuttle on the right does bear a striking resemblance to the Argo. Some variant thereof would certainly be appropriate. But I agree with Timo, that even a reuse or slight modification of the 2009 shuttles here would work. They are quite utilitarian and not tied to any specific era in terms of look, though I would get rid of the ugly jet engines on top. The Discovery shuttles throughout don't bother me, nor does the appearance of the Magee in CoM. The only thing that would bother me is if Discovery-era ships were all we ever saw, and that doesn't look like it will be the case. Just as I love that we are seeing (and will see!) a variety of different Romulans, I want a variety of different ships. That makes the universe seem rich and believable.