Well, I would go so far as to call them "decent medium infantry", but not necessarily shock troops just because they have katana.
The Go-Hatamoto is one of the better recruitable human sized shock infantry available to anyone. The 16 prot is very respectable, and is 2 better than the archer. They get 2 more HP, 1 more str, 2 higher attack, and 1 higher defense. So with the No-Dashi they are hitting for 19, while the archer hits for 16 with the katana.
Granted, the beauty of the archers is that they are very decent infantry in their own right, I just don't see the melee shock value.
