"I would wager other elements of armor werer to be sent as well, but I guess it was not publicized so I didn't hear of it. "
You didn't hear about it because it wasn't in the original Bush/Rumsfeld plan. The 4th ID is an infantry division. The problem is we don't have enough armor on the ground. That's why the additional armor deployments now, and that was the miscalculation by Bush and team.