Just figured I would start a help thread for anyone having problems with this game. Since there are major differences between Tactical elements and Meta elements, I freely invite anyone else to drop input in here to help the masses. I am still getting my brain around the Meta game, but I am finding the squad elements to be rather awesome.
My input - Squad Tactics from FM 3-21.8
The real-word strategy I have found to be very successful is to push 2 Assault guys forward to increase visibility, with Sniper and Heavy providing overwatch. I always have 1 Assault in the rear for aggressive flanking, with my Support as his battle-buddy.
My forward element get's eyes on the enemy and maybe gets a lucky hit with overwatch, maybe not. My Sniper is always in overwatch when the forward elements are moving, and nearly always gets a kill right off the bat.
Once contact has been made I begin to push my Assault elements towards the enemy, working towards getting them in shotgun/capture range. While they are moving up I use my Heavy to either blow holes in terrain with rockets, or use suppression to keep the enemy contained. My Sniper is still on overwatch.
My rear element (assault and support) is doing the bounding overwatch technique (one moves while forward guy provides overwatch) to get around the side of the enemy.
By contact +4 I have a team on the side of the enemy negating their cover, and my assault element in close range.
Basic real-world tactics that work really well in this game, I generally expect to loose a rookie every few missions (3 so far at 6 hours), but I have half-dozen officers and a large number of soldiers above the squaddie rank because they are simply not exposed as often using overwatch.