This is pretty much exactly what I've been doing; between BJJ, Striking, and MMA training, I'm looking at 2,3, sometimes even 4 hours of training 3-4 days per week. I looked at how much stuff I could take OUT of my training, not what I could add in. Several reps left in the tank on the "+" sets, all assistance is bodyweight with the exception of KB swings.
The biggest thing I've done is switch as many of my main lifts to more joint-friendly variations as possible. I'm lucky to belong to a decently-equipped gym, so I do my bench and military with the Swiss bar (parallel grips) and my squatting with the SSB. This has absolutely saved my shoulders and elbows that already get enough wear-and-tear from submissions and the volume of striking work.