A mathematical definition of detail is the sum total of information at all freq. Musically speaking, it is perception of the note fundamental with all the added harmonics, or multiples of the fundamental freq. Since further distance has the main effect of reducing the higher freq from absorption and reverberation smearing, there is less total harmonic info, esp at higher freq.
The one effect you validly mention is the gelling effect of the bass clarinet and cello to make a blended tone color. While this is an interesting synthesis of the individual clarinet and cello tones to make a new blended tone, it is debatable whether we can call that "new" detail. Suppose you have complete blending so you hear the mixture as a new color, but you can't separate the two different instruments. You gain the blend, but lose the information as what the two components are. Example--Grieg and other Scandinavian composers create unique tone colors from certain instrument combinations, but it bothers me if I am listening to a low resolution audio system or distant live sound and I cannot identify the individual instruments that make up the blended tone. Wine analogy--I am not a connoisseur, so while I might enjoy the overall taste, I cannot perceive or I have never had the training to appreciate the many individual tastes. If I got a wine tasting education, I would enjoy more aspects of the wine than I am presently able to. So the wine connoisseur perceives more details of the individual flavors, and is analogous to the front row listener. My taste perceptions are analogous to the distant listener, only able to perceive the blend.
Good musicians can blend well enough so that even up close, the perception is a good blend. Further away, there is more blend, but at a severe price of much less individual detail. This effect mainly concerns HF detail, since HF are quantitatively lost much more at distance than lower freq detail. Since you play midrange and lower freq dominated instruments, I see why you are less concerned with HF detail than I. I don't ignore low freq and midrange detail, either. The fact is that all instruments have significant wideband freq energy. The string bass has a uniquely wide freq range from deep bass to the HF from bow scraping and strong plucking of the string when it slaps the fingerboard. I get much more of the total wide freq range string bass sound (more detail) by listening close vs further away.
At Tarisio/Sotheby/Christie auctions, I have listened to good violinists comparing different violins. Even from 5 feet away, there may not be much difference that I hear. But then I compare these violins under my ear when I play them. The differences are magnified by orders of magnitude. I hear shortcomings under my ear that I totally missed from only a few feet away. That's due to the tremendous increase in detail up very close. However, close listening doesn't just reveal more flaws. It can reveal more power and beauty. In a string quartet, I once played with another violinist who had a Nicolo Gagliano. I liked what I heard in her playing. When she let me try her instrument, I was shocked and bowled over by its power and multicolored beauty under my ear. More details PLUS more beauty.