I get what they were going for with the Gargoyles since Quasimodo has to keep himself (somewhat) sane while locked in the bell tower, and they tried to keep them being a figment of his imagination vague, but I don't think they did it well enough. Like the best two examples I can think of they were hinting at this was when Frollo came up to give him his reading lessons and said "Do stones talk?", and right after the Gargoyles' musical number when Esmeralda shows up and you get a shot of what was meant to be the tapestry in the number, but it's made up of things in his room. Bringing them into the climatic battle muddled it up too much, though, but I guess they couldn't figure out a way to keep the soldiers at bay in a more natural sense.
It really was obvious they had to add the Gargoyles in there to entertain the kids, but if they had toned down the wisecracking, I think they could've worked as extensions of Quasi since they acted kinda like his conscious at times. I give at least Laverne a pass since that was Mary Wickes' final role and she (Laverne was a she, right?) gave the best advice to Quasi in his lowest moments. Jason Alexander was either a miscast or a waste of good talent.