You can do that; put the dependents on the higher paying job. You should complete part 2 if you have multiple jobs - otherwise both employers will think they are your only source of income, so they will both apply the same standard deduction, and you won't pay enough throughout the year.
Because you have two jobs, you must account for the total income. You have two main options:
Option A (easier): Check the box in Step 2(c) on both W-4s. This works best if the two salaries are somewhat close to each other.
Option B : Use the "Multiple Jobs Worksheet" (on page 3 of the W-4 form) or the IRS Tax Withholding Estimator. This gives you a specific dollar amount to enter on Step 4(c) (Extra Withholding) for one of the jobs.
Help with W-4s