all you need to do is to create the class which will act as the “master” then have the specific enemy classes be a child of the master. if you want a different skeletal mesh for each enemy you can either add the mesh in at the child level or add a mesh to the parent then set the value of the mesh in the details panel for each child (the second option is the way to go really). as for behavior, that depends, if your using behavior trees then you simply set a different tree for each child enemy, if using just scripting then you will have to have the script in the child.