Generals Minions should gain XP for thier general and should give XP
At the moment one of the biggest gameplay issues that us RTS players have is that there is no reason to split off the minoins from the generals. They are not strong enough to kill towers or assasines without thier general, and they shouldn't be.
There would be a reason to split off the minoins if they could gain XP for thier general by killing creeps.
To balance this out, the minoins should give XP to whatever kills them.
The generals would have the advatage of being able to gain XP from unoccupied lanes but if an assasin comes into one to those lanes it is a nice XP target of him.