I'm not gonna say who I think is the worse, but I'm gonna leave my two cents here.
Artists have bad days, artists sometimes do work that's heavily out of their comfort zone, and artists always improve over time. Yeah some of the art in this game aren't as great as others, but please don't let it be all that artist will be known for. Critiquing and having opinions is totally fine but I think it's fair to give them a chance to redeem themselves.
Lloyd for example is considered as one of the worst by many for multiple reasons, but Pikomaro has some outstanding work like Sumia and Charlotte. Lachesis is given flak for being too "moe-blob", along with a couple others by Miwabe Sakura, but they've honestly improved a lot of the course of FEH's lifespan, which can be seen on twitter and their GD Mist.