This is not just wrong...
This is trash...
Oda rewrite whole BM character for that point. We know that BM was introdiced as crazy mastermind, who could set up Red Wedding just for her goal, who didn't care about Luffy in WCI case she knew that he will be captured and he was. Her part of really becaming insane was her weakness from one hand, but from other it was her strong side, case in madness she became most dangerous. This Big Mom was Yonkou who did not feared Kaido and home come to made Alliance.
That character dissapeared in Wano, case now Big Mom became stupid, also she became really weak, case her potraying as O Lin or LinLin here was just for luls.
More important that SH now even not struggling withher, they deal with her like a scrub, while as we remember Robin wasn't able defeat even Diamante.
So yes, this is obviosly ass shit writing, and Loda said rhat this arc will be similar to Marinford?!
Also I fear that even final arc will be like this ... this is trash and I'm not enjoying it at all.