It's not exactly that easy. Facing an entire army of Titans that only think to eat them, they win in the long run, but with casualties. The titans seem to have no end what so ever, and seem to necer run out of stamina. While the characters from the shows listed do run out evantually. I am not saying that the titans win, but it's not as one sided as you think. Aot verse doesn't stand a chance, but they fight the good fight.
No man, they don't, incase you're forgetting you included the top tiers of the selected verses, and apparently none of them are weak, Aizen himself solos without even trying, Toriko can solo without even exhausting, pretty much everyone can, stamina isn't a neccasity when the whole cast pretty much give them an ass whooping, the Titans aren't even slightly the formidable opponents to stand against people like the top tiers of the HST altogether, even one top tier of the given verse can solo the Titans without even putting an actual amount of effort into it, just put kizaru or any admiral from one piece and he's more then capable to rape the AOT verse casually, no Titan is doing shit to akainu, he simply melts them by summoning metoers which melted tons of iceberg and boiled the sea water around marineford, kizaru kicked a guy way taller then him through multiple city blocks, and adding logia intangibity, the titans eat them, nothing happens. Hit them nothing happens, kizaru just stands there and fires lasers until they all vapourise due to his DF which won't exhaust him either, ohh and I'm forgetting aokiji, he freezes all the Titans and breaks them.
And moreover ulquiorra, Lanza spam, titans die. Aizen walks in, the Titans fall on their knees and repeat the phrase "Aizen sama"
