THIS WILL OVERWRITE YOUR HENCHMENT FILE.
Ergo, if you already have some tweaks to your Henchmen, this will overwrite it.

But don't worry, there is a very easy work-around

This also contains the Ivan tweak that gives him the 2 machine guns and a concussive grenade
Whilst also changing Rambo to have Ivan's Rocket Launcher, 
this is to prevent Ivan from blowing up your base constantly.

To install WITH any Henchmen mod you must do the following:

Go to
 Evil Genius\DynamicResources\Custom\Characters\Henchmen

Open up the Henchmen file in question with a text editor, here is Ivan as an example:
 00503-Henchman_Ivan.desc


Then paste this code into it:
AreaEffect
Continuous=false
Radius=6.0
Frequency=1.0
ScaleEffect=Loyalty +0.1
ScaleEffect=Attention +0.1
NumFilters=1
EntityType=Minion

Save and repeat for each character you want to have this mini-aura.