To suggest that anyone who HASN'T been winning knows about the GE is crazy. But I honestly believe that guys who HAVe been winning and have won, indicates they know a thing or two. There is only 1 B3 winner and 2 WCs every year (NT)....for the NTs their nation says a lot about it in terms of size and the number of users who have completely thrown away their team/never done anything but train also helps....but the guys who get the WC get some credit. At the end of the day the BBs should look to these guys for some input, not just ignore them.
On the other hand, take any one of these teams, and have him start a new team in, say, Italia. They're still the same people and still know the engine as well as they did before, but not only are they not winning the B3 any time soon, it may well be 10 seasons or more before they're getting a sniff of the top league. And it may be even harder if they can't rely on having a financial advantage that came with an early start date, and have to build the arena with today's economy rather than the one from early seasons.
Now, of course, if the question is how does the engine work when almost nearly identical teams of incredibly high-salaried players are played in essentially the same tactics over and over, naturally, nobody but the teams that are doing it would have any reasonable input at all. But well over 90% of the users of the game (and that's generous) will never come close to that level - but perhaps there are fellows (Manon, for example currently) who have experience with different tactics and players builds and can contribute information on how those players and tactics perform against a similar level of competition. B3 level players for the most part don't have the luxury - I'm not sure if you're one who's said it, but a major reason given against outside offenses in the elite level of play is that it would be too expensive to have the players needed to make it work. So on the economy of those issues, sure, the B3 players know that perfectly - but how many of them have real experience playing with and against those outside-focused offenses to know how they actually perform in the engine? Would a rejiggering of the salary formula fix the issue, or is there just not effect from certain outside skills, for example?