Sorry for the delay!
Here's a grot-focused list using Destruction allegiance:
(General) Orruk Megaboss - 140
-Command Trait: Bellowing Tyrant
-Artifact: Battered Talisman
This may initially seem as an odd choice to lead a grot army, but hear me out. He's a very resilient hero thanks to a strong armor save, a 'save' against mortal wounds from the artifact, and the ability to get extra wounds by killing enemy heroes. Because of his durability he can stand next to your front line grot units without worrying about dying too easily, and his bravery 8 is very useful with bellowing tyrant to use on units like squigs that are normally bravery 3! If you fancy an all-grot army, you can use the below option instead:
(alternate General) Grot Warboss on Squig - 120
-Moon Cutta & Git Shield
-Command Trait: Bellowing Tyrant
-Artifact: Battered Talisman
With 6 wounds and a re-rollable armor save this guy is among the more resilient of grot heroes. Don't let hit combat-oriented profile fool you though; as the general you need him around to use inspiring presence and bellowing tyrant to boost your army's resilience against battleshock so keep him protected (ideally in cover) since he will get ganged up on in combat.
(Battleline) Moonclan Grots x60 - 360
-Pokin' Spears & Moon Shields
-Boss with Barbed Net
-Grot Flag bearer with Barbed Net
-Bad Moon Icon bearer with Barbed Net
-Gong Basher with Barbed Net
-5 regular grots with Barbed Nets
This is the front line of the army, they'll want to be spread out in front of other models so that they take the charge fist. They should have inspiring presence, and the hit penalty provided by nets will make them an effective tarpit.
(Battleline) Moonclan Grots x60 - 360
-Pokin' Spears & Moon Shields
-Boss with Barbed Net
-Grot Flag bearer with Barbed Net
-Bad Moon Icon bearer with Barbed Net
-Gong Basher with Barbed Net
-5 regular grots with Barbed Nets
The second unit is the same as the first, but should be positioned slightly further back since they won't have inspiring presence. When the front unit gets killed off put inspiring presence on this unit so that they can take over as the front line. In the meantime they are a good target for bellowing tyrant if the squigs don't need it.
(Battleline) Gitmob Grots x60 - 270
-Grot Bows & Slashas
-Boss
-Flag Waver
-Hornblower
Protect these guys by putting them behind the moonclan grots.
Moonclan Grot Shaman - 80
Gitmob Grot Shaman - 80
These two heroes are magical support, each has a useful spell on their warscroll that can make them game-changers if they get it off at the right time. Obviously very squishy so they should stay behind other units, and even then they will probably die over the course of a game if the enemy has even half-decent shooting/magic.
Cave Squigs x15 - 180
This is a powerful close-combat unit but also one that is rather vulnerable to battleshock. To mitigate this keep them behind your moonclan grots so they can counter-charge enemies that get stuck in combat. The larger unit size means not all of them will get to attack at the same time but means the back side of the unit can string out in a line to keep them within 5" of herders. If you need to save points you can reduce this to a 10-squig unit.
Grot Squig Herders x2 - 20
Grot Squig Herders x2 - 20
These guys just run behind the squigs to buff them, two separate units means they can't all die to the same attack.
Mangler Squigs - 240
Mangler Squigs are a glass cannon. They can do a ton of damage but crumble quickly if attacked themselves. You can either keep them back behind your front line to counter-charge or put them on a flank to throw forward in a suicide charge early on. Against an enemy who has a lot of shooting they will probably die before reaching combat, but that's OK since it means your other squishy units like wizards and squigs survive that much longer.
Spear Chukka - 120
Spear Chukka - 120
Use these to snipe enemy characters. You'll want to keep these next to each other since they receive a bonus for doing so. If you fancy spending a bit of extra money you can swap them out for forge world
Squig Gobbas instead, be sure to use their
updated rules.