My take on the cash vs cap is this:
the salary cap expenses for player salaries are basically covered by NFL TV money that is split evenly between the 32 teams. So spending close to the cap isnt a problem salary wise. The bills can afford it. This is the what the cap covers.
What the cap does NOT cover, however, is the actual # of dollars spent by a team in a given year in cash. TKO's signing bonus counts against the cap this year, but since he was paid the bonus at the time of signing, he's not getting any of that cash this year, only his salary. So while he may count say 6 mil against the cap, he will only receive 4 mil or so in actual cash payments this season.
Its turning into a "cash" league, because the higher revenue teams generate more cash than the lower revenue teams. So even tho both us and washington have the same cap limit, washing has much more cash to spend on signing bonuses. If they generate 100 mil in cash, thats 100 mil then can spend in signing bonuses this season, to clements, freeny, etc. If the bills generate only 25 mil in cash this year, thats 4x less cash we have to give to potential free agents.
So snyder can spend 30 mil for a SB for clements, and the bills realistically would NOT be able to match it, because we lack the cash that the redskins have.
hope this helps.