It'd be pretty awesome if you could train with your followers at swordplay, would it not?
That's technically how you'd start being able to use a sword, practise, not by simply going up to a frostbite spider with one.
If you approve of this idea, what would you do? How much would you put into this system? I'd like to know.
Maybe I actually will post this in as a suggestion for TES VI some point. But not now.
*Update*
Yes I do mean actually fighting your follower. I should have made that clear. Sorry.