I used the tips in this video from youtube to get the trophy (solo).
Rogue Trooper Redux - Long Haul Stronghold Trophy (solo)
-The secondary weapon of choice is the mortar to which you can kill / destroy almost anything from one to three hits [use it a lot];
- Friendly fire [OFF];
-You can "push" the GI that you must protect to a corner.
-The Stick Grenades only explode in contact with enemies, leave several in their path;
-Micro-mines also help. Same strategy as Stick Grenades;
-With enemies close by, don't get too close to the Gi you must protect, as it will rain grenades at your position.
- In the video example, in the position next to the GI, you will have refills for: mortar, stick grenades, sniper ammo and life.
- Watch out for an enemy sniper who appears in a certain position and at a certain time during the match. He can kill the GI with a single shot.
I hope this tips can help you guys. 🙂