Hey guys finally playing my first game tonight vs matty's grey knights, having not played for a long time i was wondering should i take a librarian or or an extra 5 members(inc missile launcher and plasma gun)of my tactical squad? From the fluff i would presume grey knights are pretty immune to warp power but????????

Hard to say for sure, but a combat squad of codex marines is pretty meh, i'd stock up and outnumber.

That said, if i was taking 1 HQ i'd take the libby instead of a captain.

were playing 1000pts so im
Taking
captain combi weapon and power sword
5 man scout sqd
5 man tactical
5 man assault
land speeder with mm and assault cannon
venerable with plasma and powerfist
5 man devestator sqd las/plas/mm/hbolter


so do i add more tactical marines giving me a missile launcher and plasma gun + melta bombs for the assault sqd or do i take the librarian as a 2nd hq.
Currently built for flexibility hence no expensive terminators before anyone mentions it!

I'd drop the captain and keep the libby, the libby will help the army as a whole more than the captain will, and a GK character will kick both their heads in in combat which makes the captain somewhat redundant. fill out the taactical squad and then if you have points (and models) add some wounds to the Dev squad.

The flavour of force you've built will remain intact but you should have made it a little punchier and more resilient.

Cheers for the advice dave but i went for the extra men in the tactical sqd and im glad i did. Played the scouring and i won with only 2 men left on the table(guess which! )
but i can now also see the advantage of having the extra wounds in the devestator sqd as they got wiped by turn 3 just as they were getting targets.