Now that patch 13 is out alot of changes have been made to units and now 3v3 and 4v4 matches are possible. Before I played 1v1 and 2v2 games okay but in 3v3 and 4v4 I'm terrible. There's alot of things going on at the same time and i have no idea what I should build and what I should do. So much question is, during 3v3 and 4v4 games should I go for straight up high teir units like BCs, Carriers and Broodlords or is that a bad idea?
I havn't had much chance to play 3v3 or 4v4 and I think a lot of people are in the same boat as you at the moment. The thing I will stress is that the more players there are involved, the less your own skill independently contributes towards a win. I would suggest trying to co-ordinate your team by just throwing a basic plan together at the start of the game. I have found a lot of people seem to be responsive in doing this and can generally do quite well. Unfortunately you're bound to get team mates who just want to play as if it was 1v1 and ignore their team mates completely and there's nothing you can do about that. I think that there is no set way to do good in 3v3, although if you can set up a plan with your team at the start of the game, all of your roles within the group can be made clear. It's quite a nice idea to remember that in 3v3 and 4v4, a team rush at the start of the game is lethal if un prepared. You mention higher tier units. This is potentially a good idea because a 3-4 player combined team of such things, presuming it's not done very badly so you have a good set up of units in there, especially considering that Sentry Forcefield can be be trampled by larger units such as Thor and Collosi now. Although I can't answer directly because i'm currently quite inexperienced as are most. Anyway, that's all i've found so far, although please keep in mind I am also inexperienced
You should in your team decide who is going to tech hard etc. Usually on the 4v4 map the players in the back can tech easily. Also I think as a zerg player you'll be better off with muta/ling and then a transition.