Use bigger flowers in your church wedding decorations. Smaller arrangements can use tiny filler flowers, but you need larger headed flowers or more heavy masses of small flowers on church arrangements.
As you place flowers on the high side of the candelabra, be careful they don't interfere with any lit candles. You don't want to hide the beauty of the flames nor get any flowers too hot!
I've added alstromeria on the lower right, near the middle. Note how the flower heads point out towards the side. Your arrangements must be three dimensional, so they look good from all sides as well as the front.
A dark carnation in the low right is cut short, keeping it closer to the middle.