New to the game and looking for advice on the following list:

Ringwraith, Mounted (2/14/2)
6 morannon orcs w/shield
4 morannon orcs w/shield & spear

Grishnak w/ shield
6 morannon orcs w/shield
4 morannon orcs w/shield & spear

Gorbag w/ shield
6 morannon orcs w/ shield
4 morannon orcs w/shield & spear

Captain of the Black Guard
1 Black Guard Banner
5 Black Guard
5 morannon orcs w/shield & spear
1 Mordor Troll

10 Might/46 Models

Why have fewer spearmen than sheilds in the first three warbands?

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"Draw your sword with a heavy heart, but swing it with a heavy hand"

Only own 18 with spear.

That makes sense.

Here is what I see. You've got a lot of might but your heroes are not very strong duelists. At 800pts things like Boromir, Ambur, Gil Galad etc. start to turn up. The wraith and troll might your best bet for dealing with something like that but a stronger melee hero is worth considering. Even if it just using your troll to proxy as a chieftain to take the place of Gorbag. Or perhaps a black marshal on horse with lance to create multiple threats at different places on the field.

Keeping your banner with the man killing power of your army (the black guard warband) is good since they and the troll can make better use of it than anyone else but a second banner is worth it if you move the troll as described above.

Lastly, without any fast moving or shooting units you've only got on game plan and that it to rush the enemy. Assuming you've got heroes that can use heroic march that is good. You will be needing to do that in a few scenarios.

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"Draw your sword with a heavy heart, but swing it with a heavy hand"

Thanks for your thoughts. Now I'm toying with getting rid of Gorbag & Grisnak and taking Gothmog instead. It gives me a heavy hitter and he has heroic march (neither Gorbag nor Grisnak have it). I'll put him on a Warg for a larger threat radius:

Gothmog, Shield, Warg
7 Morannon Orcs w/ Shield
7 Morannon Orcs w/ Spear & Shield

Captain of the Black Guard
1 Black Guard Banner
5 Black Guard
5 Morannon Orcs w/Spear & Shield
1 Troll

Ringwraith (2/14/2), Mounted
6 Morannon Orcs w/ Shield
6 Morannon Orcs w/ Spear & Shield

Only thing I don’t like about gothmog is that he is S4. All the top tier heroes are D7+ so you’ll still be wounding on 6’s. Shagrat is really the only S5 alternative so maybe consider him. Gothmog does have some good special rules though.