There is nothing new about skill challenges we didn't have in 3x. The Medieval Players Handbook alone has two even cooler kinds of skill challenges, one based on debates and one based on making things. In 2e using proficiencies and way
back in 2004 using skills I have always preferred important tasks to require rolls in several skills, rather than one. And this assumes the plenitude of skills in a 3x environment, let alone a skills desert like 4e. For a battle I want to see a character's strategy, tactics, logistics, morale, and anything special they might want to try. All before the battle starts. Moving troops around, redeploying, spotting opportunities, using reserves all require more checks.

To me a major battle is about a series of skill checks by a commander and unit to unit combat. Not the commander in combat himself, although there can be some of that.

Although certainly not an opportunity for everyone to be differently equal. There are things for everyone to do, but the burden of command lays on the shoulders of the commander.