Is there a way to do this with a console/script command? or mod perhaps?
I can understand when the game first came out, they probably wanted to not have too many sprites on screen to prevent crashing player's computers and of course it can unbalance the game too.
But if you're not concerned with that, it'd be fun to summon up a genuine army of aerial servants, invisible stalkers, skellies, carrion crawlers, wyverns, etc.
I know you can do some stuff with project images, but I have SCS installed which I think stops most of that.
I seem to remember in the first BG you used to be able to use the wand to summon up huge hordes of monsters, which I found fun.