Question About Big Voices

I have a question.  I was reading the article in Classical Singer about Dolora Zajick and the Institute for Young Dramatic Voices. With the Swedish-Italian method, are there changes made for voices that are large?  Is it healthy vocally for voices of any size to work on the tiny whistle concept? I assume so, but after reading the article, I'm wondering in what ways large voices are hampered.

Actually the Swedish school became noticed for the development of the bigger voices. Many of the singers that came from Sweden in the early 20th century were Wagnerian singers like Kirsten Flagstad, Karen Branzell, Torsten Ralf, Joel Berglund, Set Svanholm, and later Birgit Nilsson. The tiny whistle concept, or small head voice exercise, is not only healthy for all voices but it is especially important for the larger voices. A naturally large voice has a stronger tendency to sing big, at the glottis, than the smaller voices. Being big at the glottis makes the voice harder to coordinate and keep balanced. This causes a loss in efficiency and register balance. It also causes a loss of focus and acoustic energy in the tone which makes it harder to sing with ease and be heard. As a result the singer feels a need to sing louder and push the tone bigger. There is a quote by Flagstad that she said to a younger colleague to the effect of, "we big voices tend to sing loud all of the time and we're the ones that don't need to." Because of the heavier orchestration and larger characters it is easy to fall into the trap of singing big. This will kill a voice regardless of its natural size. So they need to use the voice with care to make sure they are depending on pure vibration and good resonance to amplify the tone and achieve acoustic energy and not resort to singing loud. It is the difference between singing loud and singing with intensity. Loudness doesn't carry through the hall very well. Intensity does and with much less effort. There is an opposite effect that happens. The smaller the voice is at the glottis the bigger the effect in the hall and vice-versa.