Well, considering this is a 50th wedding anniversary cake and not a wedding cake, a 3rd (top tier) for the first anniversary would not be necessary. I’m “funny acting” about the tiers being so close in size. What you could do is separate tiers with separator plates to camouflage the size similarities. If you’re going to go with a 10" and a 12" you may as well go with the barrel cake. As for the flowers, I love the ranunculus or you could go with rosettes or find a pretty stencil and ice over the stencils to make the decorations seem dimensional.
~ Marjorie ~