Well, like I was saying, they probably upped the difficulty when they released it on the Xbox360 version.
The thing with the Genesis version is that the enemies generally had some pretty stupid formations that they refused to break, and didn't really react well to proximity of your characters. They would hold formation rather than actually come after you when you're within range, and you could simply rush them.
If they did the same to you then yeah, Shining Force 2 would've been your absolute nightmare. Enemies would come out of the woodwork and waste no time charging towards you, and they did massive damage in that game, and also had attacks that would bypass your defense rating, making sure to do the same amount of damage to your HP no matter how high you leveled your characters.
Shining Force CD wasn't hard, but it was harder than SF1. SF3 though, is the one to dread.