Another cool thing with the Lictors is they can go to ground in ruins for a 2+ cover, then if you bring them into synapse in your next turn (easy w/ 3 Flyrants) they can still do their thing. Combine that with making Mawlocs not scatter and they have a whole lot of synergy. LVO is known for its very good terrain, so that obviously helped.
Nick's Scout army is deceptive (I played a bunch of games against it to help him test going into the event), he puts a bunch of really tough, offensive units in your face and makes you want to kill them (Centurions, Lysander/Meph Command Squad, Lascannon devs down field) but if you focus on those then the Scouts will make you pay; either by getting into twin-linked rapid fire range or just taking every objective on the board. The Scouts are also very flexible being able to infiltrate, outflank, go in the spare pod, combat squad or not...
Really just two good generals with lists they have practiced plenty with.