Hi unto all!
To change from one technique to another is called "Henka-waza", changing technique. From my experience this is not excouraged until around 4th kyu until some great absorbtion of kihon waza has undertaken. Henka waza is a semi-advanced concept. Mastering henka waza takes experience and time. But like some things, it will happend. An example may be that you find it necessary to go from a sankyo to a kokyunage.
I may dissapoint some if not all by saying that I do not favor the shodokan style from which, I believe, is based on the Kenji Tomiki teachings. I have my opinions about Tomiki-ryu and I will keep them to myself.
I do not like to categorize aikido as being "hard" or "soft" but if I had to say, I came from an extremely hard background in aikido. Toyoda-shihan and Kobayashi-shihan and their top students and particularly hard in flavor. I could tell stories about this, but why?