I think if you're doing jitz and taking 9 days to train your whole body I would think that is fine personally. I did jitz and then lift on the same day until I was 38. Did a week rotation and I remember on Tuesdays being so fucking sore I had no idea how I was going to get my workouts in that day let alone the rest of the week. Jitz was easy as we had this saying, maybe you have it, or maybe you'll find value to it one day. It was "the hardest part is walking through the door". You know you'll get in there and get on your back, roll around do some stretches and someone will usually make a joke or 2 and your ready to go. Plus I think it helps if you move blood through your body to decrease soreness
That being said I am going to be the big 46 tomorrow (I got a gift registry on amazon if you need it) so I highly doubt at this age I could keep up with a schedule like I had in my 30's, though if I could, I would at least try. I am on blood thinners so no martial arts anymore for me. Also, I have had times in my life where i was busy working a lot and could only train my body every 8 days, it worked very well but was not doing Jitz at that time.
hope this helps