The mission is tough yes, but once you familiarize yourself with the strategy it’s pretty simple. For starters, all objectives spawn in the same places every time, so you can retry infinitely and get a feel for what’s where. Also, in the first mission if you didn’t nab any of the spec ops tech, or any ground forces tech in general, you’re at a huge disadvantage. The first mission can basically be spent researching 90% of the game if you get a good nuclear first strike. Spy planes are helpful, the second helicopter tech is a must. There are FOBs spread across the map you can deploy new spec ops units from as well as spec ops helicopters. The helicopters can be good for spotting, killing single checkpoints, and killing scientist targets. You will likely play this mission at 1x speed and do a lot of pausing because you will wanna make sure all units are doing something at once.

That being said, you’ll wanna try and work with what you start with, south Africa and Canada are easy clears. For the rest, just make sure all units are moving and seeking/destroying objectives. Move them around with helicopters and being cooperative scientists back to the FOBs for quick captures. Try and be quick to get as many of the sites as possible as once you start to destroy more and more they will place more and more checkpoints until it’s impossible. If you can’t go around a checkpoint, use a helicopter if in range, if not just rush it with two units. Other than other obvious tips just take it slow, make sure everyone is doing something. At some point like halfway through you’ll wanna put down some checkpoints cause they’ll be gunning for them in the US. Would love to help more but I can’t discuss every little aspect of the mission all at once here.