Hello all. I've finally made time to expand on my iron hills stuff and had a few questions about their stuff. I currently own 24 spears, two commands, and The Champions of Erebor

Are mattocks useful or is it just strictly better to stay with the shield and spear?

How are the chariot and goats?

How are the crossbows and ballista?

Thanks in advance!

In a strength 4 defence 8 army I never have seen a point to use mattocks. Maybe there useful as your kill squad where you put them in a tuff situation against something thats really tuff could be wrong tho. My option ur going to a tournament leave them at home just save to do shields spears. Watch the battle of five armies extended edition chariot scene thats what you will be doing on the battle field its a beast. Goats there heavy cav expense but ya there pre good everything in the iron hills army is awesome just expensive.

They look cool, which is why I was asking. I might buy some for completion's sake. As for the other dwarf factions, are any worth splashing in that's not heroes? I know how good Khazad Guard are, just curious about other things

The chariot and to a lesser extent ballista can probably be useful in the right circumstances, but with both being rather expensive, not until larger games I imagine. Generally, artillery isn't great in normal games (you may have the occasional fantastic hit, but are more likely to have entire games without one as well). The chariot I haven't seen in use personally, but it certainly seems great fun!

For the time being, however, I would recommend crossbows and a few cavalry figures. Being slow dwarves, having a ranged weapon greatly increases your threat range and opens new strategic options. Cavalry is very useful for scenarios that require you to take objectives etc. If you like them, you can always add more and have a small warband of mounted troops led by Dain or a mounted Champion of Erebor. As for the mattocks, like many two-handed weapons they are useful in small numbers. Having one or two in every warband of spears allows you to bash enemy heroes or mounted troops to the ground, while a two-handed piercing strike should be able to hurt most things. Losing out both on a shield and shieldwall is a big penalty however, so more than a few such troops will probably hurt your line rather than help.

EDIT: Also: welcome!

I'll probably pick up the rear guard for now and try to get everything painted. Thanks for the tips

Personally:

Chariots look like they have a lot of potential (at the very least, to draw attention away from elsewhere, but it gets D6 shots a turn and can put out a lot of hurt through combats too).

Goats seem great because you get that little bit of speed for objection-claiming and their special rule for charging means you may be able to avoid taking damage if you do somehow lose the fight (and if you win, getting two attacks with double strikes at S4 with the War Spear's +1 to wound is damned nice). However, they're pretty expensive points-wise and only D6 (so prime targets for shooting compared to your D7/8 main troops) - might be better to ally in some friendly cavalry, but these are pretty models and thematic and the Throne of Skulls rules can be kept if you keep pure.

Crossbows are basically a must. You can arm them with spears and use them as your second rank in a shieldwall if you fancy too. But the other Dwarfish armies have S3 shooting at 18" range, S2 shooting at 24" range, throwing axes or nothing (barring hte other ballista). Here, you have a chance for S4, 24" range and D6 (instead of the S2, 24" range, D5 rangers) - it keeps you in the running for a shoot-out with ease and can whittle the enemy as they approach you as well.

Ballista looks like it could be extremely useful too - not only does it do hefty damage to a target (as well as not scattering as far as most siege weapons) and not need line of sight itself to shoot, but it also has splash damage (can hurt models nearby the target too, disrupting their formations through fear or damage) and, additionally, prevents shooting across its own shot as well (and gets a free Heroic Shoot every turn anyway!) - it can be used offensively, defensively and for small amounts of area control. I'm sure there are other bonuses (incuding it's so pretty), but it's not a cheap unit and probably better for slightly larger games (although I imagine devastating in smaller ones - that being said, it makes it harder to reach objectives yourself due to having even fewer numbers than before).

Lastly, the mattocks (and this will apply to Goat Riders with them as well, although I'll add a note about them after too). I know this was your first question, but I wanted to comment on the others first, basically! Personally, I despise two-handed weapons. Unless you have Burly and/or Weapon Master (where you negate the -1 Duel Roll penalty), they are far too damaging to yourself to make use of the bonuses. The fact you have the choice of Piercing Strike or Bash for the special strikes is a nice bonus - I don't like to use Piercing Strike much any more though as Dwarfs are tough and, unless you win that fight (you're S4 anyway, so don't usually need the extra strength bonus), the Defence penalty is devastating; Bash is pretty situational and I'd almost always rather go for the wound/kill, but there are exceptions, like trying to knock a character from his steed or if you somehow outnumber something strong and want the rest of your troops to get double-strikes and force them to have to stand after if they survive. Additionally, by taking the mattocks, you lose your shield (no shielding option - almost always useful for the generally outnumbered Dwarfs - and lose a point of Defence, dropping to D6), which also means you lose access to the bonus for Shieldwall and can't help provide that bonus to other troops in the Shieldwalls (no D8 for this model and can't help other ones get to it either).
As for on goat riders - Bash is pointless unless you receive the charge, in most cases. You get the change to knock them down from charging before the combat and if you win the combat after charging, knock most enemies down anyway - Bash then only becomes useful against non-infantry or if you didn't charge. Piercing Strike is arguably even more useless on them (again, unless charged) as you get +1 to Wound when charging from the War Spear - which equates to a roll of 2 on the Piercing Strike bonus strength (better than rolling a 1, same as rolling a 2 and 50% of the time, rolling a 3 is the same as rolling a 2 for this bonus strength wehn you look at rolling to Wound afterwards). Both of these negatives on top of the ones you already have (the point about shields and shieldwall less relevant here, obviously, but the rest still applies).
Short version, really pretty, but in-game has SO many penalties, that I can't possible entertaint he idea of using them. Which makes me sad.

A recent italian event proved that, when there are enough dice to roll, a chariot without a captain can easily go down. The crossbow on it cannot really be relied upon and it's very hard to get it where you need it, unless it's on a straight line.

I don't like the Goats very much. They are powerful but they are only D6, which means that they will be easier targets on the field for enemy archery. Plus, they have reduced movement, so cavalry units will counter them easily anyway. I've seen them having problems with Mahur's scouts...

Ballista can be useful, but they also block your own shooting and since it always calls an heroic strike for itself you cannot just shoot with everyone else first to avoid the problem. Still, I think that this is the best siege weapon for a skirmish scenario.