Traits can also be balanced by point cost systems.
For this example, I'll use Moo2.
In Master of Orion 2 you had to pick a number of racial/government traits for your empire. The better something was the most points it cost. By default you had 10 points to pick and choose. If you chose a negative you'd gain points, and could take up to -10 in penalties for 20 points of positives.
Some drawbacks of course were never picked because they were to debilitating, such as "Uncreative(basically your race is so stupid as to never let you pick what you need in technologies) and feudal(government is narrow-minded and hates science and your research is cut in half, this could cause you to be rendered 100% harmless long-run due to technology issues). But the game still had a lot of other not so severe penalties and the game also had very powerful advantage picks. But the best ones were the most expensive: Lithovore, Tolerant, and creative. You couldn't have all three(if you could you'd be unable to lose the game, trust me).
Tolerant removed all polution, made all planets reasonably good for colonization(lowered/removed maintenance, made most biome types good as terran), it let you build things so fast so quickly that some people would even ban it from multiplayer. It cost 10 picks, yes, 10.
Lithovore removed the need to farm for your race. 10 points. Because you could put more people onto science and industry, especially science. Research players loved this one.
Creative: Another high cost (8 picks, not 10 as the two above curb-stomped this one). This was the "Foo strategy" of moo 2; while you got many "free techs" as you got to research all choices, it was also so weak early on that many players found rushing it was ideal.
Just an example anyways. Picks would be things like "resistant to smashing or lethal" or "superior accuracy", high cost ones would be combat-focused low cost picks would be more economic in a sense. I would keep economic picks very low for the reason of the fact players in a game like this are likely gonna want to be the best combat-wise, but picks should balance out overall. Or just have like two separate set of point picks: One set for combat and one set for economic.