I'm still new, and was building a Slaughter Fleet list for Summer Rampage, but one of the theme abilities is messing with me.
"Cryx warjacks in this army gain Gang Fighter. (When making a melee attack targeting an enemy model in the melee range of another friendly Faction warrior model, a model with Gang Fighter gains +2 to melee attack and melee damage rolls.)"
It's the "another warrior" part that's throwing me. I thought jacks weren't warriors, so how can one be next to "another" warrior?
Eh... it's because a few ostensibly warrior models have the rule and there's a case to be made for not bothering to re-word it for warjacks/warbeasts (cf. Helga, Circle's War Puppy, Croak Hunter and Cap Rengrave).
For battlegroup, you can take it as read that the word 'another' is superfluous, but it is maintained on the rule so that warrior models that do have Gang Fighter don't proc it off themselves.