Seeing as my Halo Wars review never materialised due to various things getting in the way i thought i would instead, after playing the game quite alot recently, give some tips on how to survive online for new players.
Online you get to choose from 6 leaders, 3 covernant and 3 UNSC. They all have various strengths and weaknesses but as a general rule UNSC are stronger the longer the game progresses while Covenant are stronger at the start of the game because after a temple is built they get given a leader at no additional cost.
As the Covenant
So the 3 covenant leaders are the brute who has brute choppers instead of ghosts and brutes as his special unit, the arbiter who has suicide grunts and the prophet of regret who has elite honor guard units.
They have vortex, rage and cleansing beam respectively.
As the Arbiter
The rage mode of the arbiter is the strongest against units so if you are playing as him try to level him up as quickly as possible and then concentrate using him against all enemy units.
As the Brute Chieftan
The brute is probably the weakest although his special units are quite strong early on so use these to counter early attacks.
As the Prophet
The prophets beam does quite alot of damage and so do his fuel rod guns so use him early on to counter attacks.
Remember Halo Wars employs a rock paper scissors gametype this means that certain units counter certain units while others counter those and so on so remember look at what the other person is and prepare to counter.
If they are Captain Cutter expect to be attacked by lots of men so build either lots of jackals or wraiths, If they are professor Anders expect lots of air units so build lots of vampires and if they are Sergant Forge expect to be spammed by tanks so build lots of hunters.
A good word of advice is not to build scarabs because the opposition can focus all their fire on it and destroy it quite quickly especially if they are Cutter.
As the UNSC
UNSC are stronger once you have all your units levelled up and all your powers at max too.
The leaders are Captain Cutter, who has the Mac blast power, ODST’s and elephants as special units, Sergant Forge, who has bombing run, Grizzlys and the Cyclops Mech and professor Anders who gets freeze, hawks and the Gremlin.