So what happens to the dead marines? Is there any way to resurrect them? Can you reorganize marines to fill up squads?

I was just thinking because I've lost quite a few of them already (even the whole assault squad) and I'm on mission 5. The squads are getting smaller so that means the game will get harder. So there's a problem brewing and I'm scared at some point I realize I have too few marines to beat the next mission and I will have to start the whole campaign over.

How do you deal with this?

When you are in the room for selecting squad for mission you can click and drag marines to different squads.

You can take kit/gear off the dead but can't revive them : (

Can't seem to be able to take bolter mags off of CSM though L F

An APothecary that could recover geneseed or be able to revive other marines with say a boltpistol and chainsword only would have been awesome : D

Great game! Hope you are enjoying it .

Thank you! Wow, I didn't realize I could move marines to different squads. I'm stupid. I've played with undermanned squads for no reason :D

Makes the game whole lot more tolerable!

Thanks! I like this game a lot. Really has that 40k atmosphere nailed, especially with the models from the 2nd edition table top. And the gameplay and UI isn't bad at all.

No, it's even quite good actually, if you're not against the gameplay style of the first X-COM games and the second edition rules combined in a package ^^.
Sorry for not noticing your post sooner ! I try to come back to this forum from time to time, as I'm also still playing and modding the game, but the place isn't very lively, as you've noticed ^^'...
To elaborate on what nuieo805798345 (!) said, yes, you can reorganize at will your men into Combat squads of five. Just keep in mind that only those decorated with the Crux Terminatus will be able to (re)fill the ranks of the Terminator squad. And that's only as long as you have Terminator suits left - a number indicated when you hop your cursor above that squad's line.
It's quite important to keep your casuaties to a minimum level, as you won't ever get reinforcements - except for a small particular event - and the game's campaign is long... Quite long, especially by the current standards ^^. So try to keep your ranks as high as possible and, when you can, swap a few "Mighty Hero" of yours with green recruits, in order to bolster your reserve units' experience. Maintaining a pool of experienced reservists helps a lot to handle your your occasional losses...
Now, despite what has been said above, you don't really need to check from ammo (and so on) on your dead units. Everything which is yours will remain in your possession after a mission ends. You only need (in most cases at least) to open canisters (crates, etc.) once to pick something and all their content will, then, be transfered to your arsenal afterwards. And no, sorry, no plundering of Chaos Space Marines possible here ! Potential corruption issues involving warp tentacles, third eyes and all that ^^...