Not a sound strategy at all.
And what is 'enough backup money' - does it mean trading only 10% of your available funds on any one trade? Is it 1%? Or is it 0.1%?
Imagine having $1. You decide to trade 1c so you ensure you have ability to 'trade freely'. You make a good trade and double your money - that 1c is now 2c and your overall money is $1.01. Is this trading freely - maybe. But it definitely is trading boring. No human has that level of patience - eventually they will trade all their funds hoping for a 5 or 10% return and bam, market turns and everything is lost.
Theory is one thing - but reality is very different.