Lucius wouldn't be inclined to genuinely help the Guild. It aids him, and his queen, to keep the humans as divided as possible. In 3E, the Neverborn have Marcus for an inside ear on the Arcanists, and Lucius in a lesser but still influential position in the Guild. Titania probably thinks she can cut a deal with the Grave Spirit (she's done it before), although the Resurrectionists themselves may be a problem. Zoraida can have the Bayou folk, it's not as though Titania or Nekima take them seriously as a threat anyway...
If anything, Titania's Neverborn are probably more concerned with the Outcasts (especially Barbaros, Tara and the Viktorias) and Ten Thunders as wild cards and players beyond their direct influence. Keeping the different human factions weakened by their own conflicts doesn't take much effort - and it's not as though the Autumn Queen didn't already return to power over the Neverborn by doing exactly the same thing, without the same advantages.
Heck, who's to say that Lucius wasn't nudged into pushing Lady Justice after Nicodem? Yes, the Thunders had their motivations, but Lucius would've known that removing either of those two works to the Neverborn's advantage. As it played out, there's even a bonus - Lady Justice will never truly trust him, but he's at least proven himself a reliable ally of convenience for her, which could help limit the Resurrectionist threat.