Because one of the designers of 9th age loves and plays only Dwarves, so he ensured that his pet army is strongest.
This keeps coming up. From the same people. And is terribly opinioned.
Dwarfs are a solid army, but at the T9A forum it's generally agreed that...
a) they're not too strong
b) they lack a lot of things that make the game fun & flexible.
Dwarfs are very good at grinding, have the strongest gunline, can build a vanguard/ambush army, and can build a flying circus to annoy. Yet each of these comes with a price, and because of the unit costs, it's really hard to try to combine them. And despite the crazy march move rule, Dwarfs regularly end up milling in the middle. Just watch the battle reports.
To the issue.
Here, the Dwarf player probably pools his king, BSB, and at least one Rune Priest into the Iron Guard unit (what is it, really - Deep Watch or King's Guard?), creating a deathstar that hits hard and protects its points superbly. At least 1100 pts in one unit of 30 models. If you can stay away from that unit and beat the rest of his army, he can't win. If you must fight that unit, you need to bring most of your army in, which is only possible if you've beaten him elsewhere. So, a classic deathstar scenario. My experience and mathhammer tell me you have really hard time beating the deathstar even if you can multicharge it and grind on your terms. And because of those two greybeard units, you're unlikely to have the freedom to fight his deathstar on your terms.
Nothing in your army can kill his king. As long as there's one Bodyguard model left in the King's unit, he won't run. Ever.
His ability to grind eats away your ability to threat him with your small hard-hitting units. They become as much a liability as a potential force.
Thus, avoid the deathstar at all costs. I don't know if Light magic helps you in this. It might not be the optimal choice.
Deployment is hugely important. If he can make a well-supported push with his main unit, and you don't have the right chaff and anvil just there, it's hard to stop him. Because of the deathstar (half his points), he can effectively fight on two fronts. You cannot. So he has the option to divide and challenge you. You really need to take out one of the greybeard units early if you want to play the middle & late games from a position of strength.
A couple of comments on your list:
- I'd squeeze points somewhere to make that Greatsword unit bigger. You need numerical supremacy in cc, otherwise it just melts away.
- The Halberdiers can only work as an anvil, probably in bus formation. A little less could do.
- Magic is always fickle, so going strong on mages is a gamble. It also takes points away from the grinding units.
I'd go through the philosophy of magic in your list. Does it pose a real threat to the Dwarf player? Does it bring best synenergy to your combat units? Is it worth its points?
If you can't change your list (could happen in a league/campaign), the matchup is indeed bad.
-Z