No man is an island, it is possible to make money and yet you may not be independent. Though money act as a defence against the needs of life, but you cannot be completely independent because there things you may request or ask from other people that money cannot buy. There are people that are blessed to make wealth here on earth but they may lack wisdom to keep this wealth going.
Wisdom helps and without it, the money you have made could be in vain.
For instance, some people that has made money and thought to be independent still seek other persons wisdom to carry on life activities. No one can get everything in life and think he/she is independent.
Money can do alot (including acquiring knowledge), but the place of wisdom can not be overlooked. Just as you've said, money is a defense. There are so many people today that are defenseless not because they are not physically strong, but just because they don't have that money. Making money is one thing, while another things is to keep making the money. Knowledge and wisdom are too things that tends to work together in making money, but knowledge is like an information that can be purchased, while wisdom isn't a common thing.
There are so many people in the world today that managed to acquire knowledge the hard way, but couldn't put the knowledge to use due to lack of money. You know what, I think money, wisdom and knowledge are very essential in making one become financially independent. The feeling that you can afford certain things for yourself relaxes the mind, and give room to think about other things outside that. Unlike others that spends time thinking about how to afford basic things and also make plans for the future.