Juggernauts are very powerful, but their greatest strength is that they require an approach completely different from the one you need against other troops.  In a large fight - many juggernauts vs many troops, the juggernauts will usually win, unless the troops are high initiative archers. You simply cannot stand and fight them toe to toe.

But juggernauts are vulnerable to hit an run tactics, at least when there's only a few on the battlefield, i.e. use high initiative troops to dash in, hit them, and dash out between the juggernaut turns.  You can make this easier if you have a water mage to slow them down.

Blindness can also work well against them. Use high dodge troops, and even the back-swing will be useless. 

You can also try to get them to kill each other - give them a target, but make sure that said target is close to 2-3 juggernauts.

Then, you can also look at the specific kind of juggernaut you are facing, i.e. their traits.  Unless you are playing at very hard difficulty, the juggernauts cannot, at the same time, be fast, and strong, and have lotsa HPs.

There's many ways to kill juggernauts, the problem is if you have to fight them with troops designed with other enemies in mind.  Heavy armor for example is great in general, but against juggernauts it's only good at slowing you down.

But all this is just talk.  If you look at specific ways to deal with juggernauts, you can check some of my play-throughs.  The next to last involved killing a ton of juggernauts.  It was in .982, so a few things have changed, but the approach outlined there works quite well against everything.  At some point, I had governor heroes solo multiple juggernauts in that game.

Actually my complaint is from my side. I don't have to deal with killing juggernauts, AI does. And both AI and monster don't have a chance. My complaint is that once I get Juggernauts it is pointless to build anything else. Warg troops are useful for patrolling your borders and quick response to intrusions, but for straight up fighting there is nothing better then juggers, at least not at that tech level (medium armors and weapons). They should not have both maul and backswing, they get way too many attacks. Also their basic accuracy is way too high. I only built them from Fort cities with all upgrades (as most players will) and I could almost always count on 1st maul attack to hit as well and 2rd maul would hit very often. Most enemies died from maul attack and the rest would die from backswing once maul finally missed.

Dealing with Verga when you don't have the right units is very hard, however, I recently had to deal with an out of control Verga while playing Tarth and I ended up slaughtering his all juggernaut armies with nothing but archers and my 2 assassins champions with bows. I had his entire armies dead on the tactical map before they could even reach my troops. They have a lot of hit points but they have no defense. I'm pretty sure I would have been crushed if i was playing another faction though, so I lucked out.

It would be very nice if you made a let's play series on you tube

Please, for the love of all that is holy, DO NOT nerf Juggernauts.  They are fine as they are.  Slow, powerful, very thematic.

Other factions should get a boost rather than Juggernauts getting nerfed.  Also, high initiative horse archers kick their butts.

Edit: Yithril also don't get ranged units.  The SINGLE biggest drawback to playing them.  So the Juggernaut is there to make up for no archers.

The yrithril race does not prevent ranged attacks (the thing that gives juggernauts). The faction trait for no ranged attacks was simply a very poor design choice in faction creation. The ythril race is what should prevent ranged attacks, otherwise anyone with half a brain will simply make a custom faction without it and have the best of both.