You can only control blah blah blah

[drewal]

Is there a way to summon more than 5 creatures at a time. I believe I remember reading something about project image maybe, or simalucrum...

I am a necromancer, so project image is not available. Is there another means of doing this?

[Alson]

Just like you said - both Project Images and Simlacrums ignore the summoning limit. You can literally build armies if you're willing to abuse this.
Dundee has an hilarious picture that demonstrate it quite well.

Unfortunately, your Necromancer can't cast neither of these powerful spells.

[Sythe]

In bg 1 I created a ARmY a huge Army made up of Kobolds, Gnolls,Hobogoblins and Goblins. Sent them all straight at sarevok and man he killed most of em and I constantly summoned more monsters with me wand of summmoning but in the end he lost killled by a gnoll