you can't split everything 50/50 I agree. But traditional training also varies depending on the instructor and on the art. I know this isnt exactly alive but I'm going to use Southern Praying Mantis as an example. But just to let you know, San Da/free fighting is supposed to be a part of ALL chinese martial arts. But you also start to free fight and spar(not all the time, I've sparred with my colleagues) in the later stages of training, a time frame "comparable" to once you get your black belt?
But Southern Praying Mantis employs A LOT of partnered drills. The drills are patterned so they arent really all that alive, but there is a bit of a resistance from your partner. The benefit I would say is that it becomes instinctive for you to learn how to block an on coming attack or stick to another person's arm or when there is a bridge you know how to manipulate the sticky hands to gain advantage because you've drilled it in your head 10000x times.
I personally noticed that I can repeat parts of those patterned drills when working on some exercises outside of my kung fu class. Just like how other arts have combinations, I think of the partnered drills as combos.
Again this is all part of the non-free fighting stage of my training. So when I do, one day, get to the San Da portion of the art, well I'd have a decent sense on how to move and react. And I feel my training is actually pretty traditional
"you're going to work till you wish you were dead and then keep going.."