I'm not sure... and what was the story behind the compass?? was the compass messed up, or is the island made up of a different magnetic field or whatever...?
first of all, Locke wanted him to let go of Shannon and not freak out at Sayid. then, Locke knows about the 'others', but he doesn't know if they will attack or try to get the people to turn against eachother. then again, they may do so without any 'outside' pressure. having allies is essential
Definite 'The Stand' reference there with the sides. Locke is building his forces up. Charlie is already on his side, so is Boone and Locke sees something in Sayid that he needs too.
Locke may be building up the forces of good, so to speak. *checking people out, making sure that he trusts them. *Because this is kinda Lord of the Flies -ish, and it's human nature. *They will split into factions. *Locke is just checking his faction out, building it up so that he's prepared for when it happens. * He's now got two very devoted followers: *Boone and *Charlie. Andn I would argue that he's not going after Walt. . . he has him. Just not quite as openly as Charlie and Boone.
It could also mean taking sides agains the "others." *Let's face it,t hey seem kinda evil. *I'd want Sayid on my side too. *After all, he was a soldier.