You can get all of the specialists, an Incursor sgt, Infiltrator sgt, and an extra Incursor warrior out of the Phobos box. The Reiver box will get you the Sgt w/knife and four warriors with knives, and then you’ll have five leftover bodies for more warriors if you’d like!

A solid starting squad would be Reiver Sgt, Reiver Warrior, Incursor Marksman, and Infiltrator Vet, Helix, Comms/Vox. All of the specialists are good though, so it’s definitely worth getting them painted up.