Great work on the spreadsheet.
But 6 teams (the green 6) cannot "control their own destiny" for a 4 team playoff.
"Control your own destiny" has a long-established specific sports meaning (which Kirk tried to blur late last season), which is that, if a team wins out, they get the given destiny being discussed. Iowa "controls its own destiny" right now, that being the Big Ten West title, in that if Iowa wins out, they win the division. No one else "controls their own destiny". All other teams need Iowa to lose once or more.
Truly, no team "controls their destiny" for the playoff, since the 4 playoff teams are selected by a committee, and not strictly by the outcome of remaining games.