“That you do,” Zeus agreed and smiled. At least Hades was practical. He would have spend time with the woman he wanted for his wife before just claiming her. If Persephone protested too much, well it was hard to sire children and foster affection and a relationship on the unwilling. Not impossible. Just difficult. Hades' life was difficult enough as it was. There were times when Zeus was quite certain that maybe he and Hera should go down and help their brother clean house a bit, establish some better ways of things for the benefit of all, but Hades would not be receptive.
Perhaps taking a wife would help him manage the riff-raff a bit better than he currently did. Though, the Olympian had to give his brother credit for one thing -no matter how faulted the Underworld was, it was miles ahead of where it had been prior to Hades' rule. When those creatures that dwelled there were roaming about without any sort of authority to rein them in, those had been dark times. His brother was doing well with what lot he'd been dealt, though Zeus was unlikely to admit that to anyone other than Hera. Hades was doing well, he could do better, but it was a vast improvement over the chaos it had been.
It was not entirely unsuitable a place for his daughter to live as Queen. She'd add some life in the realm of the dead. It would be a good match.
Then he cast his brother that mischievous look again and repeated his earlier sentiment. “By any means necessary.” Zeus would never outright suggest how his brother court his daughter, that was for Hades to figure out and put into practice on his own and for Persephone to decide if she was receptive to the idea. Though, whatever method Hades chose, Zeus would back him should Demeter pitch her predictable fit over it.