Yo,
As usual you cant beat it by your self not even in pair (maybe if those two are hardcore players then there is small chance) so coop in this map is very crucial and you can really feel it. For me this map was one of the hardest and I had to start communicate much more then usual.

1st position
Early game most important player. Recommended comander is Armored assault
Gets tanks 2xT34/85 and IS-2. Its crucial to be swift you need to destroy US and OKW base and control half of the map by the end of 2nd night if not you will have really hard time. Thats not impossible because COMPs are idle till 2nd night and there isnt too much AT guns in park.
Tactic that I recommend as 1st positon is: Devide your tanks, use IS2 to destroy US base and whole sector on the other side of the river (I performed this US base r*pe 4 times and it works every time so its very possible just dont loose that IS)
2xT34/85 should start to clean river bank near High value res. points by raming soldiers on high ground and killing key units such as snipers MGs on the lower ground. When you are done leave common units to your 2nd (or 3rd) player and move out to park to destroy KTsand JAG. That one KT guarding ground under the Building can be destroy by using only1 T34 but you have 2 so use one to get close and do circles and sencond should be hitting KT back from far.... by that time you should have enough points and resourses for another IS or (I recommend) 2Ts call them and move one KT and JAG (they are near lake on the right side) If you feel like you cant beat them with 4 tanks then call your friends to help they should have at least some ATs or 3-4 tanks that could help a bit. When you dicided to strike your tanks should have full HP otherwise your chances are much lower. Strike from their back (from the left towards from OKW base) I recomend to rape that KT first since he has smaller armor then JAG and goes down much sooner +JAG must rotate his big *ss to aim at you (dont let him one tank should fire at him whole time to SHOCK crew) but KT should fall in less then 10 seconds if 3 tanks are hiting his back (one is circling as last time) when KT is down JAG must be piece of cake and there isnt point to explain how to kick his *ss and dont forget about your IS2 in US base he need to clear it in less then 10mins. After major cleaing focus on OKW player but expect at least 2 or 3 spawns of dubble KTs and one JAG (I think he should stay in OKW base) and if you are not dumb with tanks you can play cat and mouse with KTs and KT never hits your Ts + those tanks should be at vet.3 so they will be extremly agile use it against them! after that JAG should be only obsticle in OKW base (for now) with 4 or 6 T34/85 that can be problem. Destroy OKW base kill every OKW soldier (especialy AT guns then cant be on battle field because comp is collector and love to collect guns that are laying on the battlefield) after that you should be witnessing second spawn that is 2 KT and another JAG I cant remamber it clearly so pls dont stone me to death because of that when OKW is done move on Werm base. I dont need to explain it too much beacuse with 8 T34/85 and two or 3 IS2s it cant be problem even for... well you know those guys.

I hope that I didnt bore you to death I tried to shorter it as much as I can.

Position 2
We can call him maid of the battlefield since in early game he will be cleaning mess that tanks left behind
He gets three shocks I think. If player 1 will be so kind and clear key units near high res. then you can do some cleaning with your shocks ( I recomend to bring some cons to merge with shocks that where f*cked in battle) after cleaing is done CLOSE STAIRS with barbed wire there are only two of them so do it ( and yes even your side, why to let it open if points are yours). By this time you should have at least some tanks that can help player 1 to get rid of those KTs and JAG. After that you need to clear park and roads with tanks (it shouldnt be big deal since there should be only four anti-tank guns in whole park) and your shocks maid should now focus on victory point that is in building and with no tanks allowed... bring at least one mortar to help your self there.

Those are just key things that he must do other stuff is up to him
(Game isnt every time same so he need to adapt)

and finnaly last position 3
Arty guy and tamer of the f*cked up OKW and US player
In early game he needs to... well he is arty guy so what else. Just hit with hammer most crowded places (dont hit players 1 tanks, he dont like it). His major role is to keep deastroyed US player and OKW player like they are... dead. US player got 2 spawn points one is near his base and one should be in ruined city (I cant give you GPS coordinates). Expect mostly tanks such as tank hunters and buldozers. In OKW base well that maybe a bit harder because there are KTs and JAG that are spawning from this area. But besides this there isnt much other important work for him so he can do his hobby (or better, help others when they need it) + hold Soviet base because when werm player wake up you can espect sh*tstorm coming to your base. (arty should be hot red whole game there is targets everywhere. I recomend to use them later to help capture that VP point in building with no vehicle access)

COMUNICATE! and dont loose units like I have lot of resourses. Only veterans can help you when sh*t gets real.

I hope nobody felt a sleep while reading.

Thats all and good luck (and comunicate! its COOP! no solo allowed)