Hmmm, you make some good points.
I haven't played either games in a while, but I don't remember Super Guard being that strong, at least not in the second half of the game. And even when I was younger, I was pretty good at games (I cleared a lot of the memeticly impossible ones like CV1 and 3, Ninja Gaiden 1 and 2, every Contra without dying, Ghouls and Ghosts, etc. etc.).
Then again, one thing I used to do back then, is that when a turn based rpg gave me some way of playing it like an action game (super guard, or the dodging in Mario and Luigi) I'd just ignore all the regular enemies and spend the game fighting only bosses, which tended to make them a lot harder and more drawn out then they should have been, and demanding a lot more consistency. Nowerdays I know better, and just adopt a "kill everything on the path from point a to point b" which is usually fine for exp in most games, so I wonder if a playthrough might feel like a cake walk as a result.
My main problem with Paper Mario 1, from what I can remember of it, is that with such limited defense and simple mechanics, all the fights really feel like pure damage-races (often with some gimmick to exploit, but still a damage race once you've got that down). Even though the badge attacks have a bit more variety in terms of little mini-games, I think I ultimately prefer the larger parties and tactics of Super Mario RPG, between the two of them...
...then again, I haven't played that one in a long time either, I think back in 2006 or 2007? Not sure.