Ubermuk
Sticky & Sweet
Mallow admittedly didn't have much agency with her Pokemon. Even Tsareena wasn't exactly integral to her restaurant profession in terms of Pokemon/trainer abilities (which is kinda odd because they've accomplished that with plenty COTDs). It did kinda feel like the point in the end, that Mallow didn't exactly train them and treated them more like family members, though it doesn't really excuse Shaymin's lack of limelight besides a filler episode.
Unpopular opinion here but maybe Mallow shouldn't have had any Pokemon at all. Tsareena never amounted to anything and Shaymin was borderline useless so maybe she should've been another Max...