Tien is still quite serious and cool. He is never treated as a joke, never acts like one even though he certainly doesnt get his shine. In Dragonball Super, Tien didnt get the proper treatment, I agree, but he still took down an enemy that was solidly being a nuisance for Team 7 and earned Beerus' respect, using techniques and still being a serious character.
Hercule is the true joke character, there are no positive aspects for the character. He is there to be made fun of. He is a literal JOKE. Something done to provoke comedy, nothing else. He is so egocentric he thinks he is capable of defeating beings like Cell and Buu, fails miserably and lies like a ****** to fake the fact that he is weak, and yet everyone believes him.
Now Yamcha was never supposed to be a joke character. During original Dragonball and even Dragonball Z, he was still a serious warrior/character. In DBZ, his death is actually quite honorable (jokes aside) and even then, the reason why he stops fighting (feeling powerless/helpless against beings such as the Androids) is still serious, even if taken as a joke by many.
In DBS, Yamcha's character has certainly changed. He is now truly a joke character, but nothing like Hercule, which is nothing else but that. He fell from grace of being an actual serious character and is now exactly what Hercule is.
tl;dr: Tien is still serious, not a joke at all. Hercule is the complete joke character like Dan and Kanonji. Yamcha used to be serious and fell from grace in DBS turning him into a complete joke like Hercule only THEN.