Good point
Andy. Lets get right back to the original question and it is a good one. I think it is a bit like Chinese whispers. One should read the actual OP rather than the last post in the thread. The subject gets too carried away by then. For example we are going on about stereo recording and you asked about that waveform provided to you in the competition.
When I get a wave that is way too low and it is, I simply add again to the whole thing at this point. I do it in an editor such as Adobe Audition. I open every track and run a VU meter over everything and realign all levels so they have the same rms levels. VU meter won’t show you much for a sound like this so you don't need to worry about what it may be showing at this point. Use peak metering now.
I would add as much gain as needed to get the top most peak say 6 db away from 0dB FS. You now have a waveform that you can actually see in your DAW. Also you can now hear it and it might even be a bit loud so you can start dropping the channel fader on that to put it in to a balance perspective. You are doing nothing to it or harming it in any way by adding gain. If there is noise in the track then it gets louder too but by the same amount. But it was there to start with.
Have such a strong signal now after the gain addition also means when you run it through things like a HPF set all the way up and well into the sound you will still have some level left over. Any plug-ins a decent level wave is going through will be less likely to add noise (if they do that is).
When you make rms levels consistent on your tracks though before a mix the crest factor involved for each track is still set. A tracks peaks are where they are in relation to rms levels, and at track level before any processing they are where they are. I have trimmed some silly peaks down though on tracks in the editor before a mix. It is a great place to even many things up. eg a snare hit that is just louder than all the others around it and it had no musical significance but it was the drummer hitting a hit too hard!
Sorting out rms levels all the way through a track though
(on a sound especially that is high in rms compared to peak) all makes less work for all compressors that follow then afterward. It is the nicest sound of all. Better than a compressor clamping down hard on some things and not on others.
Check out all the tracks they have supplied you. Often they are in terrible shape and random level wise as well. I don't know if it just slackness or they do it on purpose to make you go the extra mile and check all your individual tracks very carefully before you even start a mix. Which you are doing of course!
So I even out rms levels where there is enough rms enegery there to read. And very short peaky transient tracks I just bring up to -3 to -6 dB FS. There is still no harm even being very close like that. Normalise to a max level is another good option for very transient tracks. eg -4 dB. Some sounds are just so short you need them that high in order to even hear them in dense complex mix.
If too many tracks/stems are heavily effected then I don't do the mix. Sometimes they do dumb things like that. In one comp I went into they distorted the vocal stem. But what if you wanted a clean vocal sound. It was not there. Midi tracks would be fun though. Sky the limit there in terms of what sound you are going to put on the midi track.