+1 to the basic "haulers" suggestion.
There's always smoothers (I'm OCD that way) and masons (I need specific types of stone blocks, peoples! <- Ok, so again with the OCD), but at the very least the dumping subset of the hauling (from what should be a nice, empty cavern or pit-bottom) is a full-time many-staffed job.
Anyone with significant (especially "better than all those currently doing the job") vocational skills will be given that task, if it's not fish-related or (except when I am training) animal-related. Anyone with significant (indeed, any >dabbling) military skills will be assessed for the military, perhaps drafted through a boot-camp unit for basic hand-to-hand before their specific weapon skills get them shipped off into a specialist unit or their lack of specific weapon skills gets them used to bolster an under-utilised unit-type for which I have may have (or may need to make) spare weapons.
I usually up my pop-caps, and a 5yo fort with >200 dwarves generally works on this principle. There are very few jobs that aren't open to sharing and will be reluctantly farmed out to other dwarves. Bookkeeper (even after absolute accuracy achieved and bringing in others might be handy cross-training for them), Trader (unless skills get utterly surpassed), architect (likewise, but difficult given the intense and uninterrupted regime of construction planning I grant my first architect-designate), the Leader/Mayor (rarely gets ousted from his position (but then he's also often Bookmaker and Trader as required, and his actual job is quite often Stonecrafter, and Legendary quite quickly once the rest has been sorted), bur also rarely gets selected as duly appointed permanent Noble).
With the Duke, Baron, Count, this guy is usually the one with the most favourable preference-set, and yet not yet indispensable in his day-job. Obviously that's not directly related to the mass of immigrants, except that as each new wave hoves into view I particularly check their preferences (prior to the choice having been made) to see if there are any more suitable candidates than whichever soul(s) I'd previously earmarked as possibilities. With a lot of variation to go on, there's significant good chance that you'll find a candidate who fits perfectly to Your Vision, and the rest can just go Haul (as can this guy, until the decision itself).
I never actually isolate immigrants from existing inhabitants, although under the new, vampiric, developments, I shall probably have to consider doing something of this kind. Organising twin-quarters to be occupied by all new arrivals, with a little production line facility in a side-room, perhaps, to keep them occupied while still in the first stage of quarantine. And probably overkill.