I would definitely try for some sort of stereo final image. You have got three sources which can be positioned and then the reverb can be added. Early reflections as well as reverb components.
One thing is I have invested in an amazing plugin called Panagement. It is here:
https://www.auburnsounds.com/products/Panagement.html You use this conunction with your current reverb. In my case that happens to be Liquid Sonics Reverberate V2. This plugin allows you to do something much more easily then just using a reverb plugin on its own, and that is to give a full 3D effect in a way allowing not only panning from left to right but front to back as well.
With a string trio like this you can use this plug-in to position one instrument to the left, the other towards the right and the third in the centre but a little further back. All three end up in this amazing 3D like space. You can actually move all three around like this. It can sound uncanny and so real it is very impressive.
The trick is to select and edit a real nice stage or room reverb and just paint that in small doses then the whole thing sounds like it is on a stage somewhere and has real depth to it. Keeping and EQ patched in before the reverb still all applies as well.