Oh I can understand the confusion on how the Dimensions work, but I think weather or not the other versions of the Ghostbusters are called by their original names or not totally depends on the Dimension. For instance in the Anthropomorphic Animal Dimension where the Ghostbusters are Turtles the Ghostbusters are called Bill, Harold, Dan, and Ernie instead of Peter, Egon, Ray and Winston respectively. Just like Ray making the comment that they saw a version of Venkman where he was a grounds keeper at a golf course. Referring to Bill Murray's character from Caddyshack, obviously not named Venkman. However they do share the same names in the RGB, EGB, and a few other dimensions. It just seems to vary among the dimensions.
Also I agree the ATC crew have been very enjoyable in this comic. I believe the trick has got to be Erik's style of writing because I found the ATC crew annoying in their movie and in their own comic which was not written by Erik. In the comic I really didn't like the characters or the story and saw no reason for it to be five issues long. But the way the ATC crew have been used in 101 and Crossing Over has gone over well with me. Especially in this issue with Holtzman feeling legitimate guilt for a problem she feels she helped cause. This is so much better than her just having a "Ho hum, Oh well Attitude." I am referring more to the extended cut of ATC where Martin Heiss goes out the window and she just says that really mean spirited, " I guess he wasn't Ghostbusters Material."
Bottom line is the ATC characters feel like real people and not just bad punchlines in this book. I think that is awesome.