I think it's fair to expect that some players knew there was something iffy going on.
This with co-investments (Wiggy, Vunipola's, Farrell, Itoje?) must have thought they were onto a good thing, and best case scenario is that they thought it was a grey enough area that it'd so be fine.
However, the wider squad players likely don't get any of those perks. Their perks will be that they get to play with the players, hopefully improving their own game.
Would someone like Ben Spencer really know anything about what the senior players are up to, would he know the details of what a co-investment involves, would he know what salaries the top earners are on?
The co investments were a surprise to everyone about 9 months ago, and I suspect that only the players with those investments knew they were happening.
That's not to say that there aren't other dodgy deals going on, but I suspect that only those involved knew the details, and the young players in particular are likely in the dark