There are so many ways you can go about this. As long as you keep seeing results, then there is no need to change your routine. You can give 3 or more days rest between muscle groups if you need to. There are bodybuilders who train each muscle group once a week because that’s what works for them. Others train each group twice or three times each week. I don’t know much about your routine, diet, body weight and BF% to give you a more specific answer. If you have been lifting weights all of your life you must know by now which routine or frequency has worked best for you.
Bodybuilding works very different for everyone. Diet and rest are also 2 very important factors when doing bodybuilding, because without one or both of these parts it will be very difficult to reach your best possible shape. I’m not sure my answer has helped you, but my point is there is no one size fits all.
If you think your body needs more time between workouts in order to grow, then take the time to rest.
There are many different styles of resistant training programs, and all I would like to say is, if it’s working for you and your seeing results, then why change you’re routine?
On the other hand, if you feel like you have hit a plateau, then I would suggest; mix up your training, and keep it safe with at least one off-day, and one day set aside for stretching and technique.
Good luck, and stay strong,
Every third day to do the same workout does not sound unreasonable at all. However, you need to listen to your body. As a general rule when it comes to recovery you should follow periods of heavy lifting with an equal amount of time of light to no training. However, this is only a general rule and everybody is different. So, while it would seem that every third day will not lead to over-training, you will want to keep an eye out for what is referred to as accommodation. Accommodation is where your muscles become used to the training program you are doing and you plateau. So, if you find your gains slow or stop it is more likely that your muscles have accommodated and less likely that you are over training.