That used to be the way but all children and their SSA numbers must be on returns.
Claiming more dependents....
The names and ssn must be on the W2, but NOT on the W4. You can claim as many exemptions as you choose to in order to make your taxes come out closer so you don’t get a big refund at the end. For example, there are physicians who make big bucks, and own farms that lose money. They adjust the automatic deductions.