Personally I'd have done what they did ladt year, traded out, stocked picks... because there were enough flashes from Fields as a playmaker. He makes out of structure plays at times that probably only Allen, Mahomes and Jackson can match.... but the in structure stuff isn't developing. The bread and butter QB skills are no further enhanced to my eye this year.
So I think if I am content Williams checks out personality wise I'd pick him were I the GM and they will still get someone willing to trade for Fields and give them a day 2 pick back possibly.