I'm assuming that Walter is comparable to but still slower and weaker to Alucard, and without his level of regeneration? If so Vergil takes this with greater ease than Dante does with Alucard. He's faster, stronger, can take anything Walt dishes out and thats him without DT.
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"Gonna need more chloroform..."
"If you look down on us, judge us, condemn us... then you shall fear us!"
Why couldn't it? Only things I've seen for durability in Hellsing is 'stronger than steel'. To be frank a guy who can shatter a 8ft statue with a casual punch could probably cut through steel with any sword (as long as this normal sword doesn't break). Yamato would cut it like a spiders web.
__________________
"Gonna need more chloroform..."
"If you look down on us, judge us, condemn us... then you shall fear us!"