Oxeagle I have sent you an email.
I agree with Robin on the hours. Very very few people fly 50+ hrs a year. That's a pretty significant budget.
How would you measure the fuel each person used? You need to be accurate on that, which tends to imply a flowmeter and one can easily tamper with the totalised figure on those. It's also not a cheap thing to install.
This is not to say that one could not build a group around a particular plane. I have often wondered why there aren't more groups built around high-end piston IFR tourers, for example (the likely answer to that one is that pilots with the commitment to get an IR or whatever are not that numerous, and a lot of them have enough to buy outright).
A zero-equity group could be regarded as inviting zero-commitment pilots (human nature really), and there is no other area of human endeavour in which so many people put so little money where their mouth is.
So, if I was setting up a group, I would start at the other end: put together the pilots first. And get them to buy a share each. If you don't find any, you can be sure as hell you would not have found them later. Pilots can add up what flying will cost them, they know how much they will fly (whether they will tell you up front what they think they will clock up is a whole different question) and most people with the ongoing flying budget of say £5000/year can dig up the capital to buy a share.
A zero-equity group, unless it starts off with a clear business plan to make money (and send corporation tax cheques to the Revenue) is also vulnerable to attack on the Director(s) of the limited company for Benefit in Kind, which is what I sent you the email about.