Dry return question

I went out to look at a steam boiler that another mechanic installed. I saw something questionable and (just for my own knowelege) wanted to get a few opinions. On a steam boiler (one pipe system)that has several dry returns they usually have a vent near the end and then drop to below the water line, in kind of a return header.

On this install the mechanic tied the two dry returns together in the ceiling ( increased the size)and then droped below the water line.



Is that ok?
It seams to me that the old timers droped those returns individually for a reason. I've been told that it is ok

Thanks, Bob