welcome, in this case we share the same passion
I believe that the criterion used by Leonid Tarassuk is;
a landsknecht a dagger where the s or 8 shaped inner guard is removed (cut off in half) to get a better parry action while protecting the wrist.
as an example, he publishes a landsknecht dagger figure 5. of the same type as one from my collection, see
http://www.vikingsword.com/vb/showth...ighlight=river
I do not support this hypothesis, I think those landsknechtdaggers have a flat side so that they can be worn comfortably along the body.
This is also supported by JP Puype in A & A of knigths and landsknechts.
'm Curious about the other seven daggers of this type in the MET, he mentiones.
I think they can be of different types then the ones with a pair of classes.
best,