The problem is not just creating one, but upkeep afterwards. This stuff keeps changing all the time (especially if you want to be as detailed as which fare codes earn partner stuff at what percentage!).

And the answers get complicated quickly. One example, as you note, is that a particular partner may not earn on a particluar fare code. Or a particular partner may only give a fraction of actual miles, and/or a fraction of qualifying miles, on a particular fare code. Or a particular partner may not give class-of-service bonuses while another partner does. But even more complicated are particular partner quirks, like BA and AA not earning each other's miles when flying US<->Europe, but earning if you fly via Canada. (You can earn AA if you fly LAX-(AS)-Vancouver-(BA)-LHR, but you can't earn AA if you fly LAX-(BA)-LHR.)

I'm not sure who is going to put all that into a table for all airlines and how and how someone could maintain it. It seems to me it has to be done on an airline-by-airiline basis, and the person interested has to search on an airline by airline basis.

The best I think could be hoped for is a wiki specific to each airline. I know there's one for AA, I don't know how many others...

Having said all that, I'm not sure how much effort is worth it for London-MAN. It's not that far, you're not going to earn all that much with anyone. This is the kind of distance for which in the US many people who just say, shucks, Southwest has a convenient schedule, the planes are comfortable enough for a short flight, so I'll fly them even though I don't collect with them and my status doesn't work there.