All things being equal.
But of course draft and displacement are affected but many things besides just width. Even tin boats with the same bottom width will often have different draft and handling characteristics.

A hull designer is like a brewmaster who has to balance out a lot of variables and make the right trade offs to come up with a desired result.

There've been a lot of glass hull innovations to come along since the advent of Lavro's 16' classic hull design, but even tho they've modified the set-up of this model over the years, I don't think they ever made changes to the basic hull because it just worked. Why fix it if it ain't broke? Lavro's 16' is to glass DB hulls what Willie's 16&17X54's are to tin. Tried and true.

Lavro specs the unloaded draft of this model at 2 1/2 inches, which is damn skinny. Combined with a glass bottom and rounded chines, makes it one of the slipperiest boats in it's class. But again depending on the type of fishing you do, the average load and the rivers you fish this may or may not be a big deal. Personally, I prefer the Lavro's smooth quiet ride by myself or with a friend or two, but if I was guiding lardos on fall and winter flows, I could see some definite advantages to the tin set up. I liken it more to the difference between a family sedan and a working truck.