MechWarrior 5: Mercenaries

Since each wave is composed of a different makeup of enemies there is no one set strategy, but instead I have general tips of how I accomplished this.

Keep in mind you will not start collecting money until you have completed the primary objective. You will know you are working toward this when you see a money counter in the center top of the screen.

Pick easier battles
I did most of my Warzones in rank 3 area, with maybe a couple in rank 4 area. The enemy 'mechs tend to be primarily light class with a handful of medium class, so easier to take down.

Keep your distance
I would generally find a hill or raised point to get a good view of all the enemies coming at me, send out some pilots to the closest enemy, and laser or AC enemies as they got closer. I only rarely used LRMs, but they can be effective against tanks.

Fight on your terms
I would always have issues staying straight or avoiding obstacles when I was in narrow valleys or caught up against a bunch of rocks or fighting in a city. Fighting in wide-open areas helped immensely, but using the terrain to isolate enemies helps in the next point.

Gang up on enemy 'mechs
As much as possible. Isolate enemy 'mechs from the group of enemies and have your pilots all engage them. They tend to create enough of a distraction, especially 'mechs bigger than you (I would give a 'mech 5-10 tons bigger than mine to my best pilot). I would generally focus on one enemy 'mech at a time before moving on to the next one.

Run circles around your enemy
I noticed that if I ran parallel to enemies, especially 'mechs, they could get some good shots in. If I ran wide circles they would miss quite a lot and I could get some great shots in. This is why I fought in wide-open areas a lot, circling enemy 'mechs where they would take ineffective shots and I could just batter their arms and head, which leads me to my next point.

Aim for the head
I started aiming for the legs early on, but if you have a good laser or AC weapon aim for the head. There were some lucky battles where I could take out 3 enemy 'mechs in 30 seconds with some well placed shots. Even you don't get a direct headshot you will hit 'mech arms which can take out their weapons making your engagements easier.

Command pilots effectively
Always be sending your pilots out to take out targets, whether helicopter, 'mech, or tank. They can take out smaller enemies quickly, but you will generally always have better aim than them and they create the perfect distraction.

Level up your pilots
I struggled a lot when all my pilots were lower than level 20. For my last Warzone mission my pilots were 28, 25, and 23.

Take out easier targets first
This is especially true if you are close to 500,000 C-Bills. No point in going toe-to-toe with an enemy 'mech when you can take out a few tanks or helicopters to push you over that threshold.

Keep the exfiltration point close
Things will get bad when you get to 500,000 C-Bills, most likely you will have one or two pilots down and be be missing a few weapons. The moment you get over 500,000 get to the exit. One time I did not follow my own advice and lost because I was the last mech standing and 1400 meters away from the exit and got picked off on my way. Do not waste a Warzone like I did this way.

Restart if things are going bad
Since these missions take upwards of 30 minutes apiece if not longer if you lose a significant weapon and haven't even gotten 100K C-Bills it's most likely faster to restart. Losing weapons too early just means you have to rely more on inept AI pilots and more accurate aim.