People not rolling in duties - can we do something about it?

[Neophyte]

There are 3 groups of people:

1) They need a specific item. (my alt at a9)
2) They need 2-3 different items in whatever order. (my alt in a10)
3) They don't need anything and just roll occasionally and leave with low rolls or leave right away. (my main on some floors if helping friends)

Group 1 doesn't want to lose a needed item to someone of group 2 or 3.
While group 1 is biggest on tuesday, it shrinks 'till monday while group 2/3 gets bigger.
Group 1 waits a bit usually, they get an advantage by waiting.
Group 2 usually doesnt wait that long.
Group 3 do whatever they want.

Neither 1/2/3 talk about loot and what group they are.

That I can still need on bolts although I would only gear classes I don't play isn't that fair-play, too. But since no one can check this...
I don't mind if I'm 2/3 that 1 use their one advantage: They can cope with waiting for a specific item.

That's the system you get with people mentioned above randomly matched together, weekly lookouts and at worst 1 specific needed item for up to 8 players per run.