So you would trade one weakness (goaltending) for another (2nd line center)?
Detroit has eight forwards among the top 180 forwards in scoring who are natural centers:
Beyond that, there are two more who are right on the cusp.
Of those ten forwards, six are natural centers. Only one is not considered a very good defensive forward.
And that doesn't even factor in Modano, whose production rate isn't quite at that level but was improving.
I know you love your Flip, but the Wings would hardly have a weakness at center on the second line if Filppula were traded for a goaltender. If anything, the Wings are super-deep at center. The Wings have played 25 skaters this season, 12 of which played through amateur hockey and began pro careers as centers. This is compared to seven defensemen and six wingers.
There's the obvious choice to split Dats and Z. But let's say they stay together. So who centers the second line? Franzen? Hudler? Helm? Maybe it doesn't provide the general all-around player Flip is, but all of them are valid choices. If Flip were dealt, with no other roster players, for a goaltender to take the reins from Howard, I would like one of these: