Well, none of the three you mentioned do poking damage, and only 1 of the two actually deals a significant amount of damage.
Y'know, I have a real hard time believing this... Tryndamere may be the most OP out of the three (especially when fed), but Garen and Wukong do plenty of damage too. I've come across Wukong players that really knew how to push against my lane. And Garen... well, Spin-To-Win + Ulti = PAIN. I don't know how you think that Wukong and Garen don't do a significant amount of damage. Both can hurt like hell given the chance. Unless I misinterpreted what you said?
Also, about poking damage, you're right there. For me, poking was coming up to a person and auto-attacking them with the occasional skill here and there for extra hurt, then just getting out of range again. Turns out the official terminology is ranged attacking without risking yourself... well, the more you know I guess lol. I think I should have used the term 'harass' instead?