At the risk of sounding stereotypical, we all know there is a certain group of people that tend to be really good at working and manipulating numbers. Tannenbaum, assuming my stereotype to be correct, belongs to that group as does Cohen I believe. Please know that if my view is offensive it is in no way shape or form intended to belittle or downgrade anyone. The best accountants typically belong to that same group. Not an absolute, but we all know it has some accuracy to it.
Keep Cohen. Make him the numbers guy. Hire Sundquist or Angelo or Gamble or Popp or whomever to be the GM.
If Cohen isn't down for that, pay Kahn or Idzik to be the team president and put one of them in charge of the money. Parcells had a numbers guy. His name was Tannenbaum. Steelers numbers guy is Kahn. Idzik is Seattles. Franchises apparently often have two dudes.
Seems like we had two numbers dudes and no talent dudes.