This may appear a random selection, but bear with me.
The GL guy is to add to the FOO party, as they don't have much in the way of local boom. They have, as the great poet Baldrick observed, an awful lot of Boom, but need some boom to go with the flashlights.
The other two, one with an Anvil assult rifle and one with a broken las gun, are intended as buddies for the snipers. the las rifle will need repair, fortunately I have a doaner.
And the anvil stuff included some bits which are doubtless intended for the underslung GL they can provide for SM bolters.
The man with the book will join the watchkeepers at Div HQ