I disagree that Norman would be a risk.
If you look at the top 20 cornerbacks. The amount of Guaranteed Money is 71% (Richard Sherman) to 33.60% (Joe Haden). Don't see any team fully guaranteeing a 5 year deal at that money.
The vast majority in the 52-56% range.
If you offer him 5 year / $75mil, which would make him the highest paid cornerback. And guaranteed him 71% of that contract.
It comes out to only $53.25mil guaranteed.
You can get out of it after 4 years. Also more specifically we're signing him to maximize a current window we have right now today. We have a small window right now, after that, we have such a huge question mark for our future that we gotta strike now. Especially knowing that we have the OLine to carry an offense. And that line is likely not going to stay together forever.
You also win one now OR try to. It gets Romo, and gets Witten out of here quicker. So we can ease any brunt of Norman's deal.