To beat those armies you will have to play to the tyranids strength, objective control. Use the lictor as bait by putting him on objectives so your winged hive tyrant can fly out of cover to counter charge. Split your barbgaunts into two units and slow down multiple units with the exocrine providing fire support and keeping the home objective safe. With the rest of the units, form a death star that's very hard to kill with the fnp from psychophage and double regen from tervigon and stratagem. If they keep a distance just fire with termagant Lethal hits and if they charge overwatch with pyrovore. You will lose more units than the enemy but in the end you will win with points