Doesn't look bad.
With all those Ravagers I'd go Jormangandr. Chaos has a Fleet built just for them, Kronos...though that might bend some feelings.
For Carnifexen it depends...in a Jormangandr "gunline" I'd go with twin Brain Leech
, and a Heavy Venom Cannon, Spores for -1 to be hit, plus always get cover when they stand still.
I put Acid maws on them for CC
, but many call me Cra Cra
, and use the +1 to hit head...YMMV
For other Fleets most folks use double sets of Brain Leeches, or one set, and some Talons. For a Tyrannofex I prefer Acid Spray most all the time. But you will not see many Tourney players using our Big Bugs, so you'd be counter meta.
Play a few and see what you like! You can also check out our vast Tyanid tactics thread!