due to a sh*tty online system that won't allow me to consistently 1v1 in competitive settings anywhere, i can only definitively say how annoying these three were in sm4sh, but that won't stop me from making an educated guess about them in ultimate.
yoshi was a pain in the neck to deal with in sm4sh. major buffs stacked on top of an increased pace in the game would probably equal to him being one of the most annoying characters to deal with. it isn't easy for me to out space him. pac-man was bad in sm4sh and never posed a threat if i saw either of them on for glory. i know a pac-man main in real life who gets good results at locals in ultimate, but either pac-man still isn't anything significant in comparison to ness, or i am a better player by far. i don't know the current state of palutena in ultimate because i have never seen her in action, but she was in the same position as pac-man on for glory.
anyways, you can probably figure out who my solo main is.