Hm, I ask because there's one stubborn character in my game who refuses to speak when set to Global. Do you know if the legionnaire NPCs can't be set to Global for some reason? My other global characters work fine and I checked and rechecked all his Sidebar fields. They appear to be the same as all my other global characters. I even deleted and remade him. I renamed him and adjusted all the scripts to reflect that. I followed Burgee's tutorial like 8 times. rrrghhgraah...
Make sure on his sidebar he has "Default" in his dialogue box. Leaving the dialogue box blank will make it so even scripted global characters don't speak.
Some characters by default have blank dialogue boxes.