No Sensei here, just a student.
I'm not sure I understand the last half of your post. I wouldn't classify "tenkan" as a technique...though in the Yoshinkan, for instance, you would see technique names such as shomenuchi ikkajo osae ichi and ni. Ichi being an "entering/irimi" technique, and ni being a "pivoting/tenkan" technique. The differentiation in Daito ryu's Ikkajo is much greater. Completely different techniques(what we would call ikkajo/ikkyo, shihonage and many others). Some of these techniques might be deemed "variations" and some distinct technques. And I don't believe ura/omote distinctions are used as separate techniques in the counting...but I should check my resources at home to be sure. Kondo Sensei has an excellent book that I highly recommend. Its available on the aikido journal website.