In the Song and Yuan eras**, internal energy was rather crucial for becoming a powerful exponent. However there were a few individuals who reached high level without much internal energy. They are: Xiao Longnu and Zhou Zhiruo.
OK, but what if you had NO internal energy during those eras... or if you only had 10% of Xiao Longnu's internal energy? How far could you POSSIBLY get?
What if Duan Yu only learned Lingbo Weibu? Did it come with internal energy? If not, can he still become the king of short distance traversing?
Well, in HSDS, Yang Xiao and Fan Yao's techniques were second to none, and yet these fancy techniques were useless against a Du-generation monk. But, the thing is, they weren't outlandishly dazzling techniques. What if you had an outlandishly dazzling or extremely weird technique?
**I purposely excluded Ming era b/c we know if you use Sunflower Manuscript or Evil-Slaying Swordplay, you can become near invincible with about 10% of Xiao Longnu's internal energy. I am interested in discussing the same scenario is possible in earlier eras or not.