You might be able to replace some units as you see it is key to tank Mathilda without killing her. She will make Faye wing of mercy to her and Faye will then block Nino from reaching the fort. Tanking Nino is very hard, tanking Faye is much easier. Do not need savage blow on Genny. Genny can be replaced with any Gravity+ staff user. Movement restriction is applied to lure Tharja with Fjorm and to cause a traffic jam on the left side.