You're leaving part of the flower's stem for a base for more flowers like the one that you are cutting. It is crucial to be aware that flowers are usually very fragile and may have to be dyed before drying,
protea arrangement, in my not so humble opinion protea should not be arranged in bunches. The flower is majestic enough that one is enough, with a little foliage. This detracts from their beauty, the colours are gorgeous.