It is ideal to do both of the things you have mentioned.
1. You can stuck to the same number of hubs that you have written - you have to move on; so you have to write more.
2. If the previous hubs are not that much informative, they are useless, so you can't just throw your work in a dust-bin, you will have to make them useful and interesting.
It is essential to perform both the tasks simultaneously.