I shall take a stab and the Maven's can correct me. Size is hard to be relevant with little comparison
1. Least Sandpiper? ( I see yellow legs but the bill while down turned seems long) would have loved to see the entire bird, it may be a Stilt, feeding habit would have been interesting. Size to #2 would help
2. Bairds Sandpiper
3.Least Sandpiper
4. Bairds again
5. Looks like Solitary Sandpiper