Because variations is a copout. If I gave you a pizza where part was cheese, part was combo, and part was veggie, would that mean that you have multiple pizzas? No, you have one pizza that has multiple flavors.
I don't see how chakra arms are considered a tech, but I added them regardless. And having genjutsu doesn't mean you need a sharingan, having a sharingan just means you naturally are talented in genjutsu. Theres no way to know if Sasuke would have proficient in genjutsu without the sharingan, but genjutsu is infact a technique on its own, so I put it on the list.