Should it be any wonder that Goku is still top dog?

[ABED]

Agreed, Tenshinhan was also a wunderkind like Goku. He was able to learn techniques after observing them once, much like Goku. It's a shame that after his great introduction he was never able to keep pace again. He was helpful several times, but I just don't think Toriyama found him that interesting.

[Bansho64]

The earthlings and Piccolo can use the same resources as the Saiyans. I really don't buy the whole "their bodies can't handle it" belief. I absolutely don't wanna hear that considering everything that has happened in this series so far. They were able to stay on King Kai's planet and Ten was able to use the Shin Kikoho which is basically putting his body under stress comparable to Kaioken and he STILL survived. Even Toei put Yamcha in the gravity room in a filler scene so they must believe the earthlings can do it. I agree that they won't get Zenkai boosts like the Saiyans but they can ATLEAST do something. Come on man, these were the people that fought in the 21st, 22nd AND the 23rd tournaments for god sake. They may not be Saiyans with transformations but they sure ain't deserving to be treated like they're being treated currently. Come one Toei!

[Zephyr]

Agreed, Tenshinhan was also a wunderkind like Goku. He was able to learn techniques after observing them once, much like Goku. It's a shame that after his great introduction he was never able to keep pace again. He was helpful several times, but I just don't think Toriyama found him that interesting.

I think Gaffer Tape, in one of his Dragon Ball Dissection videos on the Saiyan arc, made a good point. It seemed like Yamcha, Tenshinhan, and Chaozu were being phased out, due to redundancy. Krillin took over Yamcha's spot as the relatively weak every-man, Piccolo took over Ten's role as Goku's stoic rival, and Gohan took over as Goku's-stoic-rival's little buddy.

I could see why Toriyama would just have Tenshinhan suddenly stop being special or as diligent in his training as Goku, if his intentions were to phase him out. I guess it was done relatively well, what with having there simply be race-required powerups that the characters tended to use to progress; but the fact that there was still more that Ten could have done, but didn't, makes it seem out of character for him, and thus not as well written as it could have been.