With regular skipper Rohit Sharma among a slew of players laid low by injuries, the team led by KL Rahul were whitewashed after their four-run loss in Cape Town on Sunday.
With India also missing all-rounders Hardik Pandya, Ravindra Jadeja, and Washington Sundar due to injury, Dravid said the series was an "eye-opener" and that their conservative batting was down to a lack of team balance.
"We certainly could do better in the middle overs," the former India captain told reporters after Sunday's loss, which followed their 2-1 defeat in the preceding test series.
"We understand the template, and a large part of that template is dependent on the balance of your squad.
"Some of the guys who really help us balance out the squad and give us those all-round options at number six, seven and eight were not available for selection.
"Hopefully, when they come back, it will give us a little more depth, which will allow us to play in a slightly different style."
India's bowlers fared little better, with seamers failing to strike early with the new ball and spinners struggling for success.
"I think through the middle overs we need to probably improve our wicket-taking options," Dravid said.
"We do understand that's an area in the game we have been behind a little bit -- the ability to take wickets through the middle overs -- and what we need to do about that."
India began the tour by winning the opening test in Centurion before suffering five consecutive defeats across two formats.
They host West Indies for three one-dayers and three Twenty20 Internationals next month.