No, she wouldn't have.
Hayek has no acting range whatsoever.
To have a good Dax, it would require an actor/actress with a phenomenal acting range (I.e: Jeffrey Combs, Andy Robinson to use examples already on DS9) who have the talent to
show the different personalities of the previous hosts via distinct acting for each one. I.e: as opposed to Farrell's style of "I'll just
say 'Curzon did this, Curzon did that', in the most uninteresting way possible, and that is 'good enough' to pass for me having lived multiple lives".
Hayek would have been identical in the role to Farrell; which is to say, quite bad.
Additionally, for Dax to be good the writers would have had to stepped up to the plate and given her some interesting, non-generic dialogue (she's the only character on DS9 who suffered from this symptom) and make her relevant to the overall plot of the series (again, the only character on DS9 who suffered from this symptom, along with Ezri).