Or you can get multiple pelicans, ship in about 6 Scorpions and rip the base too shreds, defend the location, build a base there and move on.
I have been introduced, painfully, to the mac rush strategy in reinforcements mode. They send a scout, and mac your base, within the first 10 seconds of the match. Anyone have counter ideas? Anyways, in the later game, a scarab/arbiter team can do pretty good. Scarab leaves a path of destruction, Arby jumps around covering the scarab's back.
Grunt rush. Only dangerous as Brute Chieften. Temple>Werhouse X3>Hall. Build 2 Brutes and 5 Grunts. Send to enemy. ???? Profit.
Hornets and canister-shell scorpions are annoying. Make sure you keep retreating the scorpions so they can recharge their canisters.
I use a mega turret/1 vulture/couple of scorpions in Deathmatch. Take control of the Mega Turret, use it against someone's base, send a vulture too Mega Barrage their base, shell the base, and if they have a team of hornets/strong enemies, just keep dropping ODSTs every time they recharge.
I usually attack with massive amounts of ODSTs. The highest I ever had was around twenty or more. If I'm Anders I try to upgrade as fast as possible, and build up on Hornets and Gremlins. If I'm Forge I try tend to max out the population cap on Grizzlies and shell their bases with shell canisters. Whenever I'm playing as the UNSC, my main strategy is to rake resources in and build two barracks/air pad/vehicle depots to pump out units faster. Whenever I'm the Covenant I attack with Locusts, Wraiths, Banshees, or Hunters, along with engineers, leaders, and maybe a little extra units to be balanced against all possible attacks.
if your covies you can upgrade your base and it will take the hit for you. For unsc i don't know an effective tactic beyond killing the hog beforehand or disruption bomb....and even that may not arrive on time
A strategy my friends and I have fun with on 3v3 is a Scarab rush. Two players play Forge and one plays a Covenant. Then the Forges just build supply pads and give the other player resources until he can build two scarabs. The fun thing is that the Covenant player can get out two scarabs within 8-10 minutes and usually the enemy isn't ready by then, unless they are rushing. It's not really too effective of a strategy, seeing as it only worked 1/2 times I've tried, but it is fun when it works. My friends and I are thinking about a double scarab rush, with two players covenant, but we haven't tried it yet.
A good rush is the mac rush. Not many people do this. What you do in case you dont know know is build a reactor, then send out your scout hog to collect 50 supplies. Then run over to your enemies base and mac them. And then have you and your teammates hogs ram the enemies hog to finish him. And only the person who shot the base finishing mac will get the magority of the points so take turns.