Paul,

What you have with the VRM is something that is trying to simulate what normally is the purview and luxury of a professional studio where they might have 3-5 sets of monitors, all in the same room.

I agree with rharv - pick one as your reference and mix using one combination.

What is nice about VRM is that you remove potentially misleading acoustics in your monitoring space (Like I believe you might have by your current placement - particularly the left hi-fi speaker), with a controlled acoustic simulation over headphones.

What is bad about VRM is that it can lead to a cycle of constant questioning because of the choices available. It's akin to having access to 30 different sampled grand pianos and trying to pick which one to use on each and every track where you use a grand piano track.

Many choices is not always a good thing and can in fact be counter-productive - which it sounds like what you are facing right now. By adding in another set of speakers, you will multiply your current choice count by two, where you already have many more simulated monitoring environments than most on this forum using the VRM with phones.

Going back to your sample track you posted a couple of weeks ago - you are already doing a great job in my opinion. You've made it past many of the faux pas that we home recordists run into and have to learn by practice. I think you might introduce some new issues with your purchase of the Rode K2 microphone and the room that you are in.