You could do it manually.
In the play tab, open the relevant Sonic instance and change things like so:
For tutti strings, replace the GM Violin, Viola, Cello, Bass sounds, with [GM 049] String Ensemble 1.
Replace Trumpet, Bone, etc, with [GM 062] Brass.
You can also dedicate entire instances of Sonic to creating a section out of several solo instruments.
I.E. to build a clarinet section, you could start a new Instance of Sonic, load several copies of the same instrument (or different clarinet sounds if you can find more than one in the Sonic library) into different slots. Set them all to the same channel.
You’ll also want to set them to use the same audio Output.
Pan them about and tweak the timber (Tone Color, EQ, Cutoff, Resonance, Attack, Release) and fine tuning so each of them are a bit unique.
Direct the endpoint of your stave to the new Sonic instances as required.
Don’t forget you can save your Sonic tweaks as multi-programs, and you can also save individual slots.
There’s more. With Sonic 7, each slot can actually have up to four layers each.
You also get a pile of effects with Sonic. Including ‘chorus’. In this case since we’re sending all the slots to the same Main outputs we could drop a chorus effect in line here.
It now sounds like a pile of clarinets!
Sonic 7 is quite powerful really. One can do much with the basic waveforms that come with Elements. It has the potential to sound very good! Just learn your way around Sonic. Don’t sell it short. Crack open the operation manual and give it a browse.