You don't know how strong Yamato is. You're assuming that she gets destroyed because of your headcanon about her power level. The truth is we don't actually know how strong Yamato is. She's as strong as Oda wants to make her, and we have little idea where that is.
Nah. This would work if Oda has actually shown Yamato to be a very strong fighter against a Calamity or something. Yamato's Devil Fruit is unknown. You can't use a character of unknown ability as a hypetool.
If Oda wanted to use Yamato as a hype tool for Kaido, he would have shown her true combat ability.
We know that she's stronger than Tobi Roppo and perhaps Post Udon G3 Luffy in Base, but the strength of her Zoan and Base forms are total unknowns.
Even when Oda planned to have Kaido defeat the Sulong Dukes be hyped them by letting them destroy Jack first and show out against Kaido's Dragon Form.
Yamato's Devil Fruit is not going to get used as a hypetool without getting a proper debut first.
See above. If Oda was solely going to use Yamato as a hypetool, he wouldn't have hidden her Devil Fruit and denied her proper battles before Kaido:
- If Kaido is just going to stomp Yamato, there's no reason to hide her Devil Fruit.
- If Kaido is just going to stomp Yamato, there's no reason to deny her full fights with the Tobi Roppo and Calamities.