Let me summarize the summary of my last paragraph for any of those who aren't willing to read "walls of text". I essentially go into detail of how SM can practically obliterate any Namekian class with relative ease since the most recent change.
SM is arguably one of the few most suited classes for taking on humans such as Fighters, and Spirits along side Karma Majin, and Ultimate Majin. Reasons being immense hit rate allowing them to almost bypass Fighter's dodge, and long ranged AoEs/Flash slash to close the distance between themselves and spiritualists. Swordsmen a basic class at the core, but if you know anything about experimenting with classes you'd know SM is more of a trickster type of class. It's similar to Crane Hermit but gets things done quicker at close range. They've got Scintillation with anti-CC accessory counters Karma(same strat works on Plasma). And lets not forget SM probably the only class in the entire game capable of trashing Shadow Knights with plus 0 everything except for their sub-weapon. And to be honest they're capable of completely obliterating every other Namekian class(they can practically do the same to Grand) with plus 0 everything except for sub as long as they land the first stun. Lets imagine if neither side had decent accessory, Swordsmen would still have the advantage thanks to glaring.The reason why you don't see SMs getting very far in Budokai is because of SKs in prelims, the severe lack of geared SM, who are also skilled. I personally would place SM's overall viability in both PvE, and PvP at #1 of Mid-tier, maybe place it on High-tier. Swordsmen by a large margin is far from the 2nd least viable class in the entire game.