Did some testing on how cavalry performs when it runs through archer units from different sides, note, not charging just running through!
The first run was made with yari cav running from the flank on five units of bow ashigaru lined up in a line next to each other (the screenshot was taken after the first run) and to my schock overwhealmingly if not exclusively the casualties war inflicted on the yari cav (half lost)! Cav losses started as soon as it drove through the first bow unit.
After that I did the same with a cav katana unit with amost- if not entirely the same result!
the I lined up the bow unirs in a row facing away from the cav and ran through with a Naginata from the rear. No damge inflicted whatsoever on bow units (exept from arrows hitting my cav as it ran through).
After that I did a run with the Yari cav coming towards the front of a bow unit…no casualties