my first post was races and balance but i will say it again
UNSC
Spartans - really good for grouped combat but also 1v1, Spartans have more health and deal more damage but are slower then everyone and arnt the smartest guys/gals around
ODST- Specialize in 1v1 combat and are great being stealth and always on the move, ODST deal alot more damage and move much faster but have less health
Marine- very effective in large groups, marines are well balanced in everything to damage, health, speed intelligence but also great at mechanics (not like any other)
Mercenary- Paid by the UNSC to hunt and kill high level targets, super affective away from combat where he can snipe his enemy, Very effective long range but not very affective in close quarters, lower health then the marine, a little slower but alot smarter
Covenant
Elite- great for grouped combat, can inspire fellow troops to deal a little more damage, Elites have decent health (less then the spartan more then the marine) and intelligence, with good damage and but not very mobile except when evading
Brute- Very strong and but also very dumb. Brutes have lots of health and lots of damage but they are very stupid, they move kinda slow but when there really close to dieing they rage and move really fast
Jackel - most effective at long distance with the sniper and when close range they can deploy a shield. great damage when sniping but little when sheild is deployed. Low health and average movement and a little smarter then the average marine
Drone- very fast and very effective in large groups, They are very fast, average damage, average health and are great for fixing things up