TUV and Aontu are the obvious ones. Do they intend to only care about North Antrim and Belfast West respectively? If so, their supporters can probably be tossed into the (present) big two camps. SDLP and UUP: they got a higher profile right now cause the SDLP has two incumbents and the UUP are staking their turf early and publicly. But how will their candidates/campaigns/voters behave outside of those specific constituencies? And that's a real question, cause history tells us some will stay in their camps, some will look to the DUP/SF, and some will look to the Alliance. The NI situation is really different on a seat-by-seat basis, which complicates just polling the regional overall.
Why is tactical voting is so much less effective in NI than in England?
It's easy to see a theoretical path where SDLP/SF would carve up West of the Bann, and Alliance/SF dominate the East, yet this is never considered.