https://serenesforest.net/thracia-776/miscellaneous/calculations/
Mounted Units losing move from rescuing has nothing to do with their actual con, Mounted units effectively have 20 Con for all rescue/capture calculations. A mounted unit carrying an 11 con or heavier unit will receive a move penalty, while those carrying 10 con or lighter units will not, regardless of their own con.
Also, units with Fatigue equal to their max HP can participate in the following map