How will the Hammer problem be solved?

Sure you can.

Raynor can build a Banshee.

(Though I do feel that her W pushes a bit far.)

The issue is that she can act like Zagara. She wrecks your lane, then you rotate to deal with her, she presses Z to go back behind her towers ans just repeats the process.

Her Z is fast enough that kiting skill shots isn’t too hard for Hammer, and long enough that she’ll be out of danger when it stops. Probius was given a super nerfed version of it, and he’s not nearly as hard to deal with.