Dune: Imperium

I can offer a guide that's a 'little' less luck dependent. I used Beast, just like the previous guide, but instead I used the 'Desert Power' challenge. Because in that challenge you get troops added directly to the conflict when you select Fremen cards on your Reveal turn.

A Fremen alliance is helpful, but not necessary. I stockpiled cubes; you can get a max of 10 before you can't add any more. I also had a few intrigue cards to help, but one was the most valuable: Rapid Mobilization. It allowed me to pump in all the rest of my troops. I played another couple of intrigue cards to get past 30.

I finished the conflict with 35, which appears to be the maximum amount, because when I added Fremen cards on that reveal turn, the number didn't go up.

It still somewhat luck dependent, hope it helps!

I got this playing against the AI in the normal challenge 'The Long Game' using Beast/Mr. David Bautista.

I leveled up the Fremen track early and milled the deck to get this signet, which kept the reserve cubes high. I then relied on/lucked out with Secret card draws that let me spend 2 spice to boost my combat power. In one round where I could get the Mentat early and had my third Agent handy, I went hard into the conflict by claiming most blue/Fremen spaces and then burned the secret card during combat.

Note that all achievements in this game pop at the end game screen. I won this with a combat score of exactly 30.