I vote 3.5 I would love some kind of endless mode. After the Campaign we get a homebase we have to manage and get random generated Missons. Something like the Soldier without border idea from Metal gear.
The Missions would be procedural generated small island which you have to liberate. Not so much focus on story and character. Maybe some more fleshed out Bosses. But mainly focus on challenging combat with endgame mercs. Maybe a new Arctic Biom or new assets like different types of building styles.
The management part could have less focus on training militia and crafting on the map and more on logistics. You produce at you homebase and it takes time and money to send it to the combat zone.
This would be a big dlc or standalone game.
