It probably was two standard sleepers and a transdorm (or a standard sleeper running in a transdorm's car line and being operated and staffed as a transdorm).Hmm, I was on a #3 the whole way earlier in July which had 3 sleepers but only 2 sleeping car attendants. I wonder how this one was staffed.
Transdorms typically do not have a dedicated attendant for the revenue roomettes sold in them. They are supposed to be covered by the attendant in the adjoining sleeper. In the case of 3, there is one attendant for 330, and one attendant for 331 and the revenue rooms sold in 340. Some attendants make sure they are properly handling both "their" car and the transdorm, some kind of forget about the transdorm. That's why I kind of avoid transdorms.