In the past couple of years, the "fondant" cake is the favorite for many brides; I love to work with it... but when all finished, the weight is usually a lot more than what I like to move in a delivery.
To avoid that, when they need to serve a lot of people, I usually recommend to go with separators between the tiers, for what we call "the stacked look". So all the cakes are individually done, and with the separators as short as possible, so in the delivery, they can be just set one in top of each other giving almost a stacked look, and a much easier time to the delivery person.
The other thing we can do in those cases, is to leave a very small separation, and filled up with flowers... They are so pretty that way!
"Stacked look"
Maite