How about running both ground grots and raider grots?

With Baron and Urien deployed with each unit respectively, Urien and his unit will be 2 PTs, then he still has D3 PT to give, so Baron's grots will definitely be running on
FC, and if you're lucky, at least 1 of the units will be running with fearless too!

Add in some minimal wracks to give Baron the PT, then you have almost guaranteed-fearless on both!
May not be the best, but might be a fun idea?
It's only 925pts-ish, assuming abberations are using scissorhands...