More can always be said on the matter, but as "Why didn't they put down smoke during the landings" happens to be one of the common D-Day questions, we can also look to previous threads for answers.

• u/racecar_ray has a good overview on the consideration of smokescreens;
• u/NoAstronomer and a now-deleted user point out the practical problems of putting down smoke;
• and u/Bigglesworth_ shows where smoke caused problems for the invasion force.

Give the guys a chance!

Considering the casualty numbers on all five beaches - even at Omaha, and the experience there should not be generalised to the entire landing force - most of the guys did indeed have a chance. On the right beach, quite excellent chances.