Goode & McKendrick mention this case in passing (edited as I knew I had seen the argument somewhere and don't want to take credit for it). They claim that Huinter v Moss was absolutely correct:
When a company issues shares, there is only one piece of property, the "shares as a whole", which cannot be segregated in any way at all. If a company issues 1000 shares and I purchase 100 shares, I am a co-owner in the share capital to the tune of 10%. It does not make sense to say that I "own 100 shares", that is not possible as the individual shares simply do not exist at all.
If I then want to transfer 50 shares on trust to my friend, with me holding them on trust, it doesn't make sense to ask "which 50 shares", there are no '50 shares', that property doesn't exist, all that happens is I am now legal co-owner of 10% of the share capital, but half of that is held on trust. Or if I transfer them outright, I co-own 5% and my friend co-owns 5%.
The fact that there may be physical share certificates is neither here nor there, the certificates themselves are not a chose in action (so if I give my friend my share certificates, he has some worthless bits of paper but no co-ownership of the share capital). Share certificates are not negotiable instruments likes bills of exchange, lading, etc. Shares do not have identification numbers in the UK any more (but even if they did the position should be the same since each 'share' would then be a co-ownership in 0.1% of the share capital, not a separate asset, and asking "which 0.1%" is meaningless).
edit - It's on p64 on Goode & McKendrick on Commercial law if you have it