All I know is that a very smart scientist girl was talking about how much of a Kraken you are.... and she is pretty cool, word on the streets at least. And coolness is the reason to believe people.
Now a bit seriously, as far as Duchess staying relevant, ofc she can. Just put your Mithrala directly in front of her speedwise and let her cleanse any debuffs. So your 310 Duchess gets a 311 Mithrala. Should stop any shenanigans, cause they either have to target the Mithrala to lock down, and Duchess gets to go....or they target Duchess and Mithrala cleanses the debuffs.
Most of my slow defense Duchess teams I put in have a cleanser that goes immediately before Duchess (Hakkohrn in Immunity and Mithrala with her approaching 1k resistance) and I find this works well in most teams for me.