ORIGINAL: Erik Rutins
From the flank, with Soviet ammo, a T-80 certainly could penetrate an M1A1. With all modern tanks, there is much more armor up front than on the flanks or rear, usually by a factor of three or four. Chobham armor would offer more protection if the Soviets were firing HEAT, but not against sabot.
Concur 100%.
The T-72 and T-80 share the same 125mm smoothbore gun IIRC, so T-72 would do it, too, IMO. Erik is perfectly right about the Chobham armour. The armour was introduced against HEAT tank rounds and HEAT missiles (which the T-72 and T-80 can fire through the gun BTW).
With all that can be said about Iraqi tactics and ammo deficiencies, there remain some lessons about NATO vs. WP that can be gained from the Gulf War and those do indicate that NATO had a quality advantage. I think FPG reflects the quality difference accurately, but the main source of pain for the WP side is the advantage of defending. We're looking to balance that a bit more in the first update - Rob has implemented some ideas which are being tested now and should make things a bit easier for the attacker (assuming good tactics, as always).
I did not play all scenarios, but you have to keep in mind that WP relied heavily on artillery support. WP superiority there was huge! Artillery support when attacking can decrease the defender's advantage.
Another big tool is the ability to recon the area in order to find the perfect spot for the WP. While playing, I realized that I could kill RED recon forces from a great distance. But these troops were elite! IMO the chances of detection should be lower. (But this is only a feeling after a few hours of playing and who am I to make those claims, I know zip about the game's internals.)
When you have found the weak spot, pre-plan and execute the artillery barrage and throw in your forces in two echelons, make the breakthrough and expand it. When forces crumble down to 30%, let it defend and keep the path open for the following echelons.

That's it. [;)] If the game will let me do it, then perfect!
Cheers,
CM