Pls explain how early summoning spells are useful

[General_Jah]

I'm new to D3 and have started my first game past the tutorial. I've read the manual and believe I have a beginers grasp on this game....

I'm playing Vanheim Early Age.

I invested some early research into conjuration and boy was I disappointed... I'm hoping you experts can show me the error of my ways...

1) What useful strategies are there for these early ritual and battle summoning spells?

I'm currently Conjuration 3 and none of the units really seem all that worth it. I've revived wights, banes, scorpions, wyverns, Hawks, and other ritual beasts... none seem much better than the units I can buy enmasse at my captial. If these were free I could see their uses but they require quite a few gems which means you can't summon to many of them until you are completely out of gems...

thanks in advance for the tips!