People who train to use archaic weapons against other archaic weapons don't tend to fret themselves trying to justify the relevance of what they're doing -- or to be insecure about whether what they're doing is a "real martial art".
It's funny that arguments for real-ness tend to base themselves on modern applications and on lineage/heritage. Can you really have it both ways?
Maybe I should test for red sash rank in Von Steuben-ryu teppo-jutsu, which focuses on the close order musket drill-kata. Or the cannon kata.
Or is that just too obscure a ryu-ha for small-arms and artillery?