Bonnie Hunter at
www.quiltville.com doesn't insist you use these rulers, and you don't need them for the patterns. What I have heard her say is that she likes the companion angle and easy angle because she can use strips from her scrapuser's system, ie 2 1/2 inch to make the HST. She has also said that she feels it is faster to make the pieces her way rather than make bigger and trim down. She occasionally has a quiltcam where she sews and visits with anyone who wants to watch and that is where I heard the comments. Anyone who follows her blog knows she is a prolific quilter and a sweet lady.
Bottom line do it your way. You might have to start with bigger squares or strips then what she lists.