Halo 4 had that four about two missions before you never seen them again. Even those two missions, they didnʻt do much but stood around as you did all the work. In Halo 5, the Meridian soldiers are just as worse with the addition to not be able to give them a ride or hand them a weapon or at least do any damage of the sort. Even the Swords of Sanghelios didnʻt show much but the first minute on Sunaion mission then disappear.
Back in Halo CE- Reach (which include 2, 3, Odst), marines did a lot and you could possiblity keep them alive for so long throughout the mission. Some of them felt so useful to the game you just didnʻt want them to die. Even the elites were just as useful without dying so quickly.
I hope we donʻt do a lot of special operation missions with just Chief and someone else and actually join a battle with the marines.