I’m terrible at this game.
Totally depends.
I usually hold off outfitting my troops until I have a better idea of what I am facing, even if it is just indie stacks, and then I tailor the mods to those.
That said, depending on faction, I usually have some go to mod layouts.
With Vanguard, the rail accelerator gets used alot. I might add electric and then later fire ammunition, and after that the kinetic phase modulator (ignore 50% of line of sight penalties, add 30% damage.)
I just finished a game with Dvar, and I have to say I struggled with the race. It seems there are basically 2 strategies here, Trencher massing and Bulwark massing.
I ended up loading Trenchers with defense mods and Bulwarks with rail accelerators and shock ammunition.
I haven’t quite yet figured out to use their support unit, feels slightly…clunky to me.
With amazons, for example, the Biomancer can scan stuff, then your Huntresses pile on the biochemical damage. That can scale quite nicely, especially if the enemy is massing one or two units predominantly (which they usually do.)
The Dvar Foreman has a limited heal and can encourage a Dvar unit… :(
When the tanks and rocket artillery show up, by that point you have some nice explosive mods, and tanks with the later game explosive mods can reliably melt faces and tank damage.
And the artillery can dish out serious damage.
The Baron is a unique unit because you can produce it without a barracks, and is a fairly durable 3 shot repeating unit. Expensive, and a tier 3, so hard to mass, but not bad at all.
I find Dvar hardest to play!