I don't know about other people but when I eat out with my family and friends, we usually don't split the bill. Splitting the bill means paying with two or three modes of payment for one bill. Either we divide up the entire bill on how many we are then put in that money or one pays first then divide it up later. It doesn't matter if its cash or credit card. I don't know about when we order our own because frankly its been awhile since we have done that. We eat "family style" a lot of times. We order one of each - appetizer, salad and entree then put it in the middle for everyone to share. This works for us. Or on very rare occasions that we order individually, we put in the same amount to cover for the entire bill and tips. Or inform the server ahead of time to make it separate bills. I don't know, its just easier that way both for us and for our server.
This came to mind when I saw this big group and I mean big group like 15 of them when my aunt and I ate out last night. They gave the server 2 modes of payment but 3 types - cash and 2 credit cards with instructions on how much to get from each. How did I know this? Well, they were standing really close to me and they were pretty loud so it wasn't hard to hear. I saw how the server struggled with the bill to follow the instructions. I mean, it could have lessened the hassle if they told the server in advance to split it or made internal arrangements among themselves before settling the bill. Good thing it was almost the end of business day so it wasn't busy anymore. Imagine if it was. I know there are restaurants that either tell you to inform the server beforehand or don't allow it all. I know I ate somewhere and it was specified on the menu that 'no splitting of bill". I just don't remember where.
Eating in big groups is not alien to me. Their group of 15 is not big compared to us. We have been denied reservation during dinner service because it would mean for the restaurant closing half of their seating capacity. We either eat before or after the rush hour. Yes, we are that big and that's only immediate family. So if you hear "so and so, party of 40" That's probably us and that's not even half of all us and that's only my mother's side of the family. But same thing, either its split evenly among us or one pays first.