I don't like complaining a lot but I feel that difficulty levels are a bit messed up.
I am the type of player that stretches the game. I build up my defenses, gather my resources and when I decide that my army is strong enough, I attack. I never played neither RA2 nor YR on easy difficulty because I always balance my gameplay between defending and attacking and it has always work for me throughout all strategy games.
When you launch RA2 and YR, and pick easy difficulty, the game lets you go around the game at a slower pace, enemy rarely attacks you and when he does, it's just to remind you that he is there in the game with you, waiting for you to attack him. You don't have to defend your base all that much and all you need is to mass your army and just decide: "I have enough soldiers and tanks, I should just attack". When you decimate enemy's checkpoint he almost never sends troops to that checkpoint.
On Normal difficulty, the enemy becomes slightly aggressive, he attacks you just enough to keep you on your toes, to make you work your strategy, to make you balance between defending your site and training troops for the eventual attack. When you are ready, you think "I am ready to attack the enemy and I think my defenses are strong enough to prevent the counter attack, but that should not happen". Even if your attack fails, you still have strong defense for you to mount a counter-counter attack. When checkpoint is attacked and decimated, enemy sends troops at that checkpoint eventually.
On Hard, the enemy is ruthless. He constantly attacks you keeping you on your toes. Makes you focus on your defense while gradually working your way through the map, step by step, capturing the points that he had under control. If your attack fails, retaliation is usually brutal. Checkpoints are almost always "regenerated", making you rethink about the troops you used in the attack. "Should I have used more tanks instead of soldiers? More Seals instead of Rocketeers? More Tesla Tanks instead of Rhinos?"
Why did I wrote all this? I was forced to replay some RA2 and YR campaign missions on all the difficulties to compare the difficulty levels against Mental Omega and difficulties do not match. I went through the normal difficulties of the first 4 missions, I found them challenging but doable but, then I came across "Beautiful Mind" and I just crashed and after a couple attempts I was forced to go to Easy.
Not only was I welcomed by the timer but no matter how hard I bolstered my defenses and how hard I went after that damned Iron Curtain, my troops were decimated and, before I turned, all the checkpoints I went through and cleaned of enemy presence, enemies were back there. Like I was playing Hard difficulty. And then I decided to check the Official Playthrough and, although it was recorded on Highest Difficulty, the level of speed required to set up your defenses, as a new player, was insane.
Don't get me wrong, I am not bashing the entire game, only the difficulty levels because, Easy difficulty should not be THAT challenging. It should be something you pick to get a lay of the land, not to be eaten alive.