As for allies, it seems there are a ton of good options for us.
Warwalkers are a cheap add on for more lance shots
GJB keep with our fast theme and can easily provide fast scoring options for us, as well as some decent anti-TEQ fire when properly protected
Wraithguard im abit more defensive about, but their toughness goes well with our army, and being troops with a spiritseer who can greatly boost their defense by either upping their armorsave or giving them shrouding can help out drastically. Again a tough scoring option for an army that is fragile is nice.
the Crimson Hunter finally gives us a superiority fighter. Something we should of had awhile ago.
A Farseer can give us guide/prescience and double our output from ravagers/venoms. And if we are lucky can bring us doom as well.
An Autarch can add some punch to reavers, same with some shining spears.
Serpents can give us some AV12 to protect our fragile venoms and raiders.
Basically there are only a few duds in the book, but I feel it meshes well with ours as a whole. Overall Im very happy with it, and Im sure we will see a ton of DE/CWE team ups to come.