Can definitely give that back to you....
Yamato and the Samurai were quite literally pinned and defeated. Even if they went all out, there was no way they could get past Greenbull's overpowered abilities. Yamato clearly asked for help, not cause she thinks that Luffy and the others are stronger than Greenbull like you try to show it now, but because she knows they just defeated 2 Yonko and their crews and thus a single Admiral is beatable.
Your comment was completely biased and out of logic.