Saving is part of my life and I have never seen it as an impossible task that needs to be done with efforts.
It should be good for you if you have multiple sources of income, but I don't know if you need to maintain a percentage of that amount each month. Even if saving is recommended, but I don't think it's necessary to have a special percentage in doing so and just do how many you can save.
If you insist on saving a certain amount each month then you may run into problems when your source of income dries up for one reason or another. This will definitely give you a lot of responsibility so that you can or should reduce your daily and monthly needs to get the percentage that you set. You can do it, but your method cannot adopted for other users.
If you really wanted to save money from any amount of salary, do it after you budget your salary, always prioritize the budget for rent, food, water, electricity, etc. and the amount of money that's gonna left, save it. Some people failed to save any amount of money because they don't know their priorities, or does a lot of overspending it to anything they want, which is very irresponsible as an adult.