If you took Gary and Ed and combined them into one person, imo you get Ron Santo.
Gary makes some great calls at times, like at the end of the 2005 Capital One Bowl. And Ed certainly knows football. Both are Hawkeye homers.
But they really aren't that good at their jobs, which is informing people about the game as its being played. As others have said, you often don't know what's going on. you don't know the score, the down, the distance. Hell, you might not even know who has the ball. And if the running back rushes for 5 yards? They might tell you it was only 2, because they spend a lot of time correcting themselves on their calls.
That may work in a baseball game like it did with Santo, with the leisurely pace and all. Not to mention, Pat Hughes is a great play by play man who just flat out made the absurdity that was Santo's 'analysis' work.
But in football? You need somebody who can tell you what's going on in the game all the time, and who isn't going to screw it up when he does tell you.