Can someone please tell me the trick to beating Mlada Boleslav?

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I can't get off this damn campaign mission. What am I missing? Should I be priotizing my units elsewhere? Should I get a certain type of unit from the last mission?

I usually get to the point where I push NATO units out of the first objective. Then they fire rockets all over my units and I lose. Rushing towards the arty will get my units destroyed. Falling back won't do anything, and the AI's units will catch up.