Actually they just filled a script for me that was 180 Norcos that was sent in electronically by my doctor and I was the only one who questioned it because it was a mistake. They were like "nope, it says 180" and I just said I guess I won't have to come back as soon as usual.
I think that this is something that is unique to each pharmacy and even ones in the same chain will do things very differently. One Walgreens near me refused to fill a script for maybe 15 or 20 Norco because it was after hours and they could not contact the dentist as I was the last oral surgery of the day. Despite my swollen face and mouth stuffed with bloody gauze the clerk seemed to take pleasure in denying me.
I have been to a different Walgreens near our largest ER and they had no problem filling scripts for percs or vikes in the middle of the night because I am sure they cater to the hospital crowd.
Even if there's a company policy, there is a big difference in how it's interpreted so I think trial and error is the only way to really know how they operate. I have also found that some will use the database and refuse a script that duplicates an earlier one in that month (Costco) and the above mentioned hospital Walgreens does not.
Unless you are in a rural area where choices are few, it's a good idea to shop around and find the one with the best prices and least attitude. Sorry for taking your subject so wide of the topic! I just feel like I have tried them all and there is no consistency.