Cake Dilemma: A 14" Cake or 2 13"x9" Backup Cakes?

13"x9" and 14" cake pans with a spoon for reference.

I made the 2nd half of the 12" cake and another batch of neoclassic buttercream yesterday. It was daytime and Rana insisted on helping, so things did not go exactly as planned. I must have taken the syrup off heat before it came to a rolling boil, because the buttercream turned out thinner than it should be. I made a mental note to flavor this batch with white chocolate (rather than lemon) with the hope that chocolate will stiffen it a little more. When the cake came out of the oven, I noticed that one side rose more than the other. This may have happened because the tray underneath was not level, but it could also be because I failed to level the batter well when it first went in the oven--I do not know. Anyway, I had to trim a portion off the top to level it and I made another mental note to place these thinner layers in the middle so that the cake looks symmetric when it is cut. We had the trimmed top for dessert, and to my relief everyone liked it. And one more unfortunate thing, a small piece of the cake on the side broke as I unmolded it from the pan, again because I was not careful enough as I ran a knife around the sides to separate it from the pan. This will have to be masked with buttercream during frosting.

At this point, I have 12", 10", 8" and 6" cakes baked, and these (with 2 13"x9" backup cakes) will be enough cake for 275 people. (By the way, a backup cake is an untiered and undecorated cake that is not displayed. It is kept, cut and served from the kitchen. Since it takes an expert quite a while to cut and serve the real wedding cake, a backup cake is a very practical thing to have on hand and speeds up things.) This was my initial plan but now I am a little worried that with these sizes, the tiered cake may look small. It is possible to make a small cake look bigger by using pillars in between layers, but Amina asked specifically for no pillars so this is not an option. I am seriously debating now if I should forget about the backup cakes and bake a 14" bottom cake instead. The cakes are more difficult to bake as the sizes get bigger, and they become a challenge to manipulate, but a 14" bottom tier will certainly make the finished cake look grander. I am just undecided about what to do :(