But, when you are adopting a new strategy then you should not go using it right away. You should first test on paper trading; this way it seems you must have back up plans for your strategy so that you may not disturb your trading routines when you change your trading strategies.
Trading is one thing that we keep falling out of sometimes no matter the amount of care you implore in it, you make a single mistake and you may have big regret. Despite the paper trading which is same as practice, if we don't understand how to control our emotions, we may keep having difficulty in it. So as we are doing paper trading, we can still practice with small amount to build real trading emotions.
If I understand it right, both of you got that point in which will help traders to anticipate what the market will bring,
Practice your strategy using paper trading or demos will probably give you ideas about what to do when you already dealing using your money and in the other hand, using a small amount of investment to test if you are doing things correctly will enhance your chance to keep improving.
Both are useful, but yes, emotion is the thing that you really need to avoid whenever you are in this field.