I see what your saying and generally you will still use front and side images even if the concept is a 3quarter view say of a human animal etc. Makes it quicker to push out the models and have proper size. I can talk it over and see if i can do a tut soon that dont use a image plan and go off the concept only....
I am enough of an artist to draw freely upon my imagination, knowledge is limited, imagination encircles the world. (Albert Einstein)
https://www.artstation.com/kurtb