okay I'v already done a walkthru for the first level,but for those who have not read it the best setup is sniper on top rifle men in middle and michine gunner thru botom.
so since that didnt take long lets move on to level 2.
okay realy all you have to do is send all of your troops thru the top and flank them. but if you afraid of leving the bottom unprotected go ahead and leave a rifle men squad in the bottom. hope this helps!