Wario has issues with swords, no doubt. I doubt he wins any of the MUs against swordies. You just have to space better than your opponent really, that's how I feel about it. They're mostly very straightforward, fundamental based MUs from my experience. With the exception of Cloud.
They have better hitboxes, so you have to space better to prevent clashing them, because you'll lose every time of course due to theirs being disjointed. Against swordies my general mentality is to try and stay as close to them as possible while still being out of the sword's range. Gives you the most time to get punishes in.
Against all swordies but Cloud you really should be camping for waft all the time though, there's no reason to approach. With the exception of Cloud, they can't force approaches so that makes camping an even better option. They have to approach or you get free waft so you need to exploit that by running away constantly.