How about if a certain troops let say barbarian used in battle they get some exp points by collecting those exp points the result will be like;
Movement speed increases by +1 for evey set of exp points say ; 1set needs 200 exp points
2nd set need 500exp points.
3rd one need 1200 exp points
4th 2000 exp and so on
Or
There time of traning decreses 1 sec like same exp system as above :)
please how is it?

