So a friend and I are going to be attending our first sbg tournament at the end of the summer and are looking forward mostly to the doubles tournament. The rules are 500 points per person, and we want to play out personal favorites Harad and Moria. I have spoken to him about his Harad side, but I'm not sure exactly what he will be bringing yet, just that he wants to maximize the Harad 50% bow limit, so he will be using mostly watchers of karna and the cave that you can take with that (i believe he said serpent guard or raiders). As far as my moria side I want to maximize model count, but still run some of morias better models. So far I have come up with this: (please pick it apart and make suggestions I really don't know the tournament scene)

WB1
Groblog+ 6 prowlers w shield+ 6 goblins with Spear
WB2
Shaman+ 6 prowlers with shield+ 6 goblins with Spear
WB3
Goblin Capt w bow+ 11 goblin archers+ 1 cave troll
WB4
Shaman+ 3 goblin w shield+ 2 goblin with Spear

A touch over point limit but I can drop a gob if I need to

My real questions are should I try and drop something for marauders (if so what I do really like using them), and would a blackshield line be better than prowlers? Anything else I should add, I have most models for the army so feel free to suggest anything. Also suggestions for my Harad ally would be much appreciated too

I think you could certainly take this and be just fine. If you want nitpicking, here are a few suggestions I would have:

Gundabad Blackshields are great front-line infantry for Gobbos instead of the Prowlers. The Defense 6 is wonderful, and prowlers really benefit from literally prowling the flanks to jump in on combats of opportunity (to make best use of their +1 to wound trapped models rule).

I would also suggest, if possible, dropping the Goblin Bows for another unit of combat Goblins led by a Shaman. Since your partner is going to be taking a good amount of (vastly superior) Haradrim shooting, you might as well take it to the enemy. Supported D6 Blackshields under Fury are pretty tough to crack! And remember, being dastardly evil he can shoot into combats. Sure he'll occasionally kill a Goblin, but if he is killing and Elf or Dwarf for each Goblin you lose it's still a net gain.

I'd usually recommend Warg Marauders but Harad Cav will bring the mobile element they otherwise provide.

What about this?
Groblog- 5 Blackshields, 5 Moria Goblins with Spear, Cave Troll
Shaman- 5 Blackshields, 5 Moria Goblins with Spear, Cave Troll
Shaman- 5 Blackshields, 5 Moria Goblins with Spear
500 on the nose

Gives you a nice little battle line:

BBBBB CT BBBBB CT BBBBB
SSSSS SSSSS SSSSS
Sh Grlg Sh

Is this the NoVA doubles by chance? If so, I'll also be playing in that. Hope to see you there!

Nice yea we re thinking about going to Nova seems like a good time