I don't think squig herds are so good to play them in 3x if you still have your battlelines, they don't provide in anything, more troll are much better imo.
We suffer in many things, less damage without ex battalions and expansive battleline both in points and models and keywords super restrictive(all of that's bad design).
Skragrott is the big leader of gsg but still, the battlelines he can take are only stabbas/shotas and need to be the general for his CA, they should make him warlord like arkhan at least
We can do "well" with a mega-gargant as ally:
Allegiance: Gloomspite Gitz - Grand Strategy: - Triumphs: LEADERS Bundo Whalebiter (490) - Allies Loonboss on Mangler Squigs (310) Webspinner Shaman on Arachnarok Spider (295) Skragrott, The Loonking (230) - General Madcap Shaman (80) UNITS 12 x Squig Herd (160) 20 x Shootas (140) 20 x Shootas (140) 3 x Rockgut Troggoths (145) TOTAL: 1990/2000 WOUNDS: 147
That's not mine but took a 4°place recently