oh wow, yea, I can see how the bulges can make all that confusing.
For the one on the left I think it's barely a few muscles up, but hard to tell.
For the one on the right, he clearly has a very buff erector spinae, and the erector does go all the way from bottom up, so I think what's happening there is that it's simply bulging under the Latissiums dorsi, even if it IS covered by the latissiums.
It goes something like this:
Following the anatomy, this is what I think those muscles are positioned there:
I mean, that was rushed, but I think the idea is there.