Issue with VST and Mixes

I am using the EastWest Hollywood Orchestra in Cubase 8.5 Pro.

Each orchestral instrument is on a MIDI track and is using the related VST instrument and channel for its sound. I have loaded each of the sections (Woodwinds, Strings, Percussion and Brass) into their own VST Instrument.

Where I am confused is doing the mixes. For example, I can change the volume for the clarinet on either the MIDI track or the VST track. Which one should I be using? Since I am able to do this, I am thinking I am not approaching this correctly.
Also, if I want to change the overall volume of the section, I thought I can adjust the volume of the VST (brass, woodwinds, etc). However, for some of the VST Instruments it works, but other it does not. For example, when I change the volume on the Woodwind VST, all the woodwinds adjust, except for the bassoon. Yet, the bassoon is on the Woodwind VST.

Is there a better way to setup/load the VST instruments when using MIDI tracks? I thought that by having one VST instrument per section would be a better way to conserve memory, instead of a VST for each instrument. Plus, I can use the expression maps and more easily jump to channels or keyswitches to get different articulations.

Thank you for the help.

I’m a bit confused with your terminology and am not familiar with play.
I use a rack and 4 midi tracks (eg ; piccolo, 2 flutes, alto flute) separate instruments in one Kontakt instance. These get routed to a group track (along with clarinets and double reeds), woodwinds, add the appropriate reverb and to stereo out.
Others have a more complicated template, depends on your requirements, workflow and system.

You need to think about signal flow and where you want the level changes to occur. For example using MIDI to set the Volume is basically changing the level coming directly out of the VSTi. Where if you use the MixConsole’s fader the level gets adjusted after some or all of the Channel’s Audio Inserts.

A) Sound Source > level adjust > compressor > EQ > …
B) Sound Source > compressor > EQ > level adjust > …

Both A & B are valid to do, but they will sound different. Neither one is the “right” way to do it although B is likely more commonly used.

Unless you are at risk of running out of computing resources save yourself a bunch of work and go with one Instrument Track for each VSTi. And if you are running out of capacity the solution is gonna be upgrading not trying to crank out some marginal capacity by rearranging your mix of VSTi’s on Instrument/MIDI Tracks (see: deck chairs, Titanic). This will only produce marginal differences and not always in the way you’d think. Search the forum for several long threads on the topic.

Most folks doing huge orchestral templates end up using Vienna Ensemble Pro to host their VSTi’s.