You can run as many imstruments as your CPU can handle, basically. There are many ways to optimize settings and workflow that can do wonders for your setup and playback.
Download and watch all the VSL videos that apply from your "My VSL" area.
Watch the Sonor videos that deal with optimizing Sonars playback engine (set buffer jigh when playing back!)
Get as much RAM as you can afford!
Get as many SSDs as you can afford!
Unerstand the best way to optimize your DAW with VEPro. I have a video on Youtube about that subject if you wanna check it out here...
I use Digital Performer but you'll see the big picture at least if not more. I have two more vids coming.
Optimize the VSL Instrument Player once note entry is done.
Do you have MIR?
Look for more Sonar/VEP videos and READ THE MANUAL!
Hit me back or PM me with questions if you want. You'll be up an running in no time.
Cheers!
Steve
Regards, Steve Steele https://www.stevesteele.com