Sadly, the game doesn't have variety at all. The characters differ only by their E/R skills and thus they can all play/build the same way. The most dangerous part is Aatrox Phase 2 (Swords), which can wipe your team. This strategy works for the other maps as well because they are just lesser versions of Aatrox.

Not even Leona/Illaoi/Briar can tank Phase 2 Aatrox Swords in a meaningful way for long. Therefore the strategy is UNGA BUNGA DPS: more DPS = faster TTK = less chance of a wipe.

Pick this exact build no matter what character you are using:

Annihilator - EXP

UWU Blaster - Ability Haste

Bunny Crossbow Bunny Mega Blaster - Crit

Ice Armor - Armor (best defensive skill, blocks a full instance of damage no matter the number, eliminating need for other defensive stats, also even with maxed hp/armor/regen you can't really tank Phase 2 Aatrox).

Base E skill - Whatever stat Evolves it (e.g. Briar Health, Xayah Pickup Range)

For the last stat pick Damage. If your base E skill overlaps one of the above, you can pick 1 additional stat, probably Projectiles. It's also reasonable to swap EXP for Projectiles if you find EXP too late.

If everyone picks Annihilator, you are basically guaranteed to reach the boss. The Annihilator Evolve gives EXP bonus. Using just 3 annihilators, we reached level 43.

Then, all you need to do is ensure you have enough single-target DPS to crush Aatrox, which you accomplish using the above build.

For Augments, take anything that increases DPS (more damage, more ability haste, more projectiles etc). Cross Country is the most broken augment.

Using the above strategy, there is basically no difference between the characters at all, save that Jinx/Xayah have slightly more DPS than the other characters because their base E skill is basically a 2nd UWU blaster worth of damage.

You can use this strategy for the complete Aatrox with all characters mission.