The entire game is a plus/minus question. I started a thread a few days ago titled "Shortstop". It's because I "never" skimp D at SS but I've got a situation where it might be the best thing to do.
In your case, I think your D is making your pitching worse than it is. You don't have to go overkill by doing a 180 wrt O/D but you did need Leskanic out of CF and/or Hayes from LF/Ewing from 3B. I wouldn't think you'd need all three to make your D "reasonable". IMO, Mijares at 2B might be better than Gonzalez because of the offense he'd give you. But, if you wanted to work Ewing into LF/RF/1B some(he'd be average/above average at all three), you could use Mijares/Gonzalez 3B/2B.