Again you are assuming. Firstly you are assuming that because you use cavalry and didn't explicitly train the skill, that yours has never increased. Secondly you are assuming that both characters started at the same base skill level. You can't 100% guarantee it cause you have no idea what level your opponents skill started at or what gains he has made.
If I know what mine is, and its the lowest you can have then yes I do. But, perhaps I'm just wrong on how the code works. (But I do know how much Brom has even though he hasn't trained it).