from: http://gaming.stackexchange.com/questions/36380/how-can-i-find-my-followers-skills-and-stats
All followers have different stats that are determined by their level. Their level is fixed as soon as you enter the zone and the NPC is loaded. Once that happens, you cannot change their proficiencies without the console.
To find out exactly what the stats of the follower has, you have to perform a series of console commands:
Move up to the NPC you want to query.
Open up the console and click on them. There should be a small text string that shows up in the console, that is their unique ID.
Start querying their stats via the command getav. For example:
getav health shows you their health
getav sneak shows you their sneak ability
You can use the command: showinventory to see what their default armors are, even if it doesn't show up when you ask them to open their inventory in the dialog menu.
If you ever wish to 'level up' your follower since you have leveled after meeting them:
Remove all gear from their inventory (at least ones that you don't want to be blown away.)
Select them via the console again
use the console command: disable
use the console command: enable
After this, the follower should be scaled to what your character's level is.
On top of that, most npcs (including followers) are hard level capped at 30, 40, or 50. J'zargo is unique in that he has no cap (there may be others, but he is confirmed). He still, however, suffers from the skills bug. The only workaround for it is to disable/enable.
Eventually a mod will fix it, because if Bethesda tries to fix it, our followers will start running backwards and die in 2 seconds because of their -100% magic resistance.