It's almost pointless to compare both, because they were made by totally different studios in different buildings / cities :
Antz wasn't Dreamworks. It was made by Pacific Data Images. All the important people behind it ( directors, producers, supervising animators ) came from PDI, including Eric Darnell, Tim Johnson, Bradford Lewis, Patty Wooton, Carl Rosendahl, Raman Hui, Rex Grignon, Tim Cheung, etc. They were all visual effects people
Shark Tale, on the other hand, was made by the hand drawn department of Dreamworks, being their first CG project. Nearly all the important people behind it came from Prince of Egypt / El Dorado, including Bibo Bergeron, Bill Damaschke, Nick Fletcher, Sam Michlap, Seth Engstrom, Doug Cooper, Lionel Gallat, Fabrice Joubert, etc. They were all traditional animators
It bears mentioning that Antz was made in a pre 9/11 america, unlike Shark Tale
