This is the hardest part of 3v3(and 4v4). If you play the game like 3 seperate 1v1 games you will get run over when the other team combines. Then they have the upper hand because you were decimated and now its a 3v2.
You have to watch the minimap and track where the other armies are. If you only see 1 enemy then anticipate a blob assault on another area of the map soon.
Try to retreat your army and let them have the territory if you are getting rekt and your team mates are not helping.
Anticipate and help your team mates.
If you lock down territory and are safe, place mines and defensive structures everywhere. Then gradually move your army to your team mates area if you feel good about your defensive stance in your area.
OKW is my worst faction so I have no good advice on where your trucks should be I still bring my medic truck close to the front but I do not upgrade it to FRP until very late game. This way I can still soft retreat to it. Or do a full retreat, select the reinforcements at my base but send the guys to the truck so they will reinforce at the truck and be ready to go back at the front.
As for the 1v1 comment, you have to be a better player and know more about the game to be good at 1v1. The maps are larger and the commanders are more effective. Team games you can play most of the game without a commander and do ok. In a 1v1 the gimmicks are much more useful. In a 1v1 someone can oorah right past your MGs and its gg. In a 3v3 your team mates may have guys coming up behind you to save you etc. In a 1v1 you have to anticipate your enemies every move. Check his commanders, bulletins, which map are you playing, etc. In a 3v3 you can just blob guys and man fight to your hearts content In a 1v1 you make one mistake and its gg. You can almost lose your whole army in 4v4s and still win.
thx for the insight, i was trying to kill the mortars before helping my teammates, it was that 120mm soviet mortar,i felt like that would kill my mg's and rekketens really fast, i wanted to flank them by moving a bit further, the match i had before this one,i did it and wipe most of the other team units, they're were spamming mg's but not covering the flanks.
I agree with you about the 1v1, i haven't played it yet because i fell like i would get crushed, i'm trying to learn more about the game before trying it.
Thx again!!!